Geology, Structure and Geochemistry of the
Mazenod Lake Volcanic Complex
by

Mark Hamilton

Faculty of Graduate Studies
Department of Geology

Submitted in partial fulfillment
of the requirements for the degree of
Master of Science

Brandon University
Brandon, Manitoba, Canada

Copyright © 2017 by Mark Hamilton

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Abstract
This study examines the geology, structure, hydrothermal alteration and mineralization
from the Mazenod Lake volcanic complex in the Great Bear Magmatic Zone (GBMZ),
Northwest Territories, Canada. Field work and geochemical data indicate that the Faber Group
volcanic lithology is comprised of pervasively metasomatized, calc-alkaline, intermediate to
felsic ignimbrite flows.
Analysis of lineaments derived from a high-resolution satellite image and measured
vertical gradient (MVG) aeromagnetic data delineate tectonic blocks defined by strike-slip faults,
including two sets of NE-trending right-lateral faults (~N50°E and ~N20E°) and one set of leftlateral NW-oriented (~N30°W) faults. Mass balance and several diagnostic residual alteration
indices (RAIs) characterize the nature, intensity and distribution of hydrothermal alteration.
Spatial analysis of the RAIs reveals a direct correlation between locally significant structures and
centers of intense alteration at Dan Island, Nod Hill and the central Bea area. The geology,
structure and pervasive alteration are characteristic of a magmatic-hydrothermal iron oxide
copper-gold (MH-IOCG) system.

Keywords: Great Bear Magmatic Zone, Mazenod Lake, Faber Group, IOCG, hydrothermal
alteration, metasomatism, mass balance, alteration indices, RAI

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Acknowledgements
I would like to acknowledge the very generous support of Dawn Zhu and BFR Copper &
Gold for providing the necessary data and funds to make this study possible. Their trust in me is
sincerely appreciated, and it is my earnest hope that they succeed in all their exploration
endeavors.
Thank you to the editors and fellow geoscientists for instruction and advisement provided
in the review and revision process. I would also like to thank fellow geologist colleagues that
have contributed to this study by publishing related cited material. The many students and
colleagues that provided insight into this investigation are too many to mention but deserve an
acknowledgement as well. Without the support of my advisor Dr. Hamid Mumin there is no
chance I would have been able to complete a project of this magnitude. I would also like to
acknowledge the support of my committee members including Dr. Alireza K. Somarin, Dr.
Austin F. Gulliver, the external reviewer Dr. Paul Alexander, and other individuals involved in
the defense of this thesis. I would particularly like to recognize the significant contribution of all
field mappers, students and contributors that took part in the extensive 2013 field work
including: Dr. Hamid Mumin, Scott Ryan, John Shmyr, Kyle Reid, Kevan Bender, Shane
Gleeson and Rashid Mumin. This thesis is dedicated to the memory of our camp manager,
facilitator and personal friend Howard Stewart. He brought our camp to life with his unfailing
enthusiasm and made it a place we all came to consider home. Thank you, Howard.

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Table of Contents
Abstract .......................................................................................................................................... iii
Acknowledgements ........................................................................................................................ iv
List of Tables ................................................................................................................................. xi
List of Figures. .............................................................................................................................. xii
Chapter I: Introduction ................................................................................................................ 1
Location, Physiography and Climate .......................................................................................... 2
Chapter II: Previous Work in the Mazenod Lake Area ........................................................... 7
Chapter III: Iron Oxide Copper-Gold Deposits ...................................................................... 10
Economic Importance ............................................................................................................... 10
Morphology & Structural Controls ........................................................................................... 13
Spatial & Geologic Context ...................................................................................................... 14
Hydrothermal Alteration ........................................................................................................... 14
(a) Sodic Alteration ............................................................................................................... 17
(b) Iron Oxide Alterations ..................................................................................................... 18
(c) Potassic Alteration .......................................................................................................... 19
(d) Tourmaline Alteration ..................................................................................................... 20
(e) Phyllic and other Hydrolytic Alterations......................................................................... 20
(f) Silicification ..................................................................................................................... 21

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(g) Other Associated Alteration Effects ................................................................................ 21
Genesis ...................................................................................................................................... 22
Chapter IV: Regional Geology and Tectonic Setting of the GBMZ ...................................... 28
Structure and Tectonics ............................................................................................................. 32
Chapter V: Geology of the Mazenod Lake Region .................................................................. 36
Local Geologic Setting .............................................................................................................. 36
Paleozoic Sediments.................................................................................................................. 41
Great Bear Intrusive Rocks ....................................................................................................... 41
(a) Sarah Lake Granite ......................................................................................................... 43
(b) Marian River Batholith .................................................................................................... 44
Faber Lake Volcanic Rocks ...................................................................................................... 41
(a) Volcanic Sediments .......................................................................................................... 45
(b) Dianne Lake assemblage ................................................................................................. 45
(c) Lou Lake assemblage....................................................................................................... 48
(d) Squirrel Lake assemblage ................................................................................................ 50
(e) Bea Lake assemblage....................................................................................................... 50
(f) Mazenod Lake assemblage .............................................................................................. 51
Hydrothermal Alteration ........................................................................................................... 52
(a) Magnetite ± actinolite (MA) alteration ........................................................................... 52
(b) Potassic alteration ........................................................................................................... 55
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(c) Tourmaline alteration ...................................................................................................... 56
(d) Hematite alteration .......................................................................................................... 56
(e) Phyllic alteration ............................................................................................................. 57
(f) Epidote alteration ............................................................................................................ 57
(g) Silicification ..................................................................................................................... 58
Mineralization ........................................................................................................................... 58
Chapter VI: Structural Analysis ............................................................................................... 61
Lineament Definition ................................................................................................................ 61
Methodology ............................................................................................................................. 62
(a) Lineament and lineament intersection delineation .......................................................... 62
(b) Analysis of lineament orientations .................................................................................. 63
(c) Analysis of the population density ................................................................................... 63
Satellite Image ........................................................................................................................... 62
Aeromagnetic Data .................................................................................................................... 62
Digital Elevation Model (DEM) ............................................................................................... 62
Field Mapping ........................................................................................................................... 62
Satellite Image Lineaments ....................................................................................................... 70
Magnetic Lineaments ................................................................................................................ 73
Lineament Density Models ....................................................................................................... 76
(a) Satellite image lineament population density .................................................................. 76
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(b) MVG data lineament density ........................................................................................... 76
(c) MVG data lineament intersections density ...................................................................... 79
Chapter VII: Geochemical Data Analysis ................................................................................ 81
Filtering Data and Handling Detection Limits .......................................................................... 83
Least Altered Representative Samples ...................................................................................... 84
Geochemical Classification ....................................................................................................... 87
(a) Tectonomagmatic Classification ..................................................................................... 90
(b) Trace Element Discrimination of Granitic Rocks ........................................................... 90
Element Mobility....................................................................................................................... 90
Mass Balance Analysis.............................................................................................................. 95
Isocons of Mineralized Samples ............................................................................................... 97
(a) Site 1, Dan Island ............................................................................................................ 97
(b) Site 2, NE of Nod Hill ...................................................................................................... 99
(c) Site 3, Bea area .............................................................................................................. 100
(d) Site 4, Nod Hill .............................................................................................................. 100
Quanitatively Assessing Hydrothermal Alteration ................................................................. 102
(a) Magnetite ± Actinolite (MA) Alteration......................................................................... 103
(b) Potassic Alteration ........................................................................................................ 105
(c) Tourmaline Alteration ................................................................................................... 105
(d) Propylitic Alteration ...................................................................................................... 108
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(e) Hematite Alteration ....................................................................................................... 108
(f) Silicification ................................................................................................................... 111
Alteration Indices .................................................................................................................... 111
Residual Alteration Indices ..................................................................................................... 115
(a) Sodium Enrichment Index .............................................................................................. 115
(b) Iron Alteration Index ..................................................................................................... 115
(c) Ca-Fe Alteration Index .................................................................................................. 120
(d) Potassic Alteration Indices ............................................................................................ 123
(e) Silica Alteration Index ................................................................................................... 128
Chapter VIII: Discussion ......................................................................................................... 132
Stratigraphy ............................................................................................................................. 133
Structure .................................................................................................................................. 134
Hydrothermal Alteration ......................................................................................................... 142
(a) Sodic Alteration ............................................................................................................. 145
(b) Magnetite ± Actinolite (MA) Alteration......................................................................... 145
(c) Potassic Alteration ........................................................................................................ 146
(d) Tourmaline Alteration ................................................................................................... 146
(e) Hematite Alteration ....................................................................................................... 147
(f) Phyllic Alteration ........................................................................................................... 147
(g) Propylitic Alteration ...................................................................................................... 148
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(h) Silicification ................................................................................................................... 148
Residual Alteration Indices (RAIs) ......................................................................................... 148
Mineralization ......................................................................................................................... 150
Implications for Exploration ................................................................................................... 150
Chapter IX: Conclusions .......................................................................................................... 152
References .................................................................................................................................. 157
Appendix I: Petrographic Analysis ......................................................................................... 175
Appendix II: Formulas ............................................................................................................. 195
Appendix III: Sample Descriptions ......................................................................................... 197
Appendix IV: Common Indicator Element Concentrations ................................................. 204
Appendix V: Mass Balance Data ............................................................................................. 216
Curriculum Vitae ...................................................................................................................... 232

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List of Tables
TABLE 1. History of work completed within vicinity of Mazenod Lake .......................................8
TABLE 2. Defining characteristics of magmatic-hydrothermal IOCGs, modified from Richards
and Mumin (2013a, b)....................................................................................................................12
TABLE 3. Adjustments made to values in the geochemical data under the detection limit ........83
TABLE 4: Selected least altered representatives of lithology ......................................................85
TABLE 5. Residual Alteration Indices (RAIs) applied to the Mazenod Lake region ................114
TABLE 6. Dominant faults in the Mazenod Lake region and their estimated horizontal offset 138
TABLE 7. Typical element mobility associated with the some of the most common Mazenod
Lake regions hydrothermal alteration types ...............................................................................144
TABLE 8. Hand sample and thin section analysis of selected rocks ..........................................177
TABLE 9. SEM analysis of sample 98197 .................................................................................188
TABLE 10. Sample descriptions amalgamated from sample booklet data, field notes and later
observations for those samples undergone mass balance analysis in this study .........................198
TABLE 11. Mass balance data ...................................................................................................217

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List of Figures
Figure. 1. Regional location of the Mazenod Project, NWT. ..........................................................5
Figure. 2. Geographic location of the study region within the Northwest Territories .....................6
Figure. 3. Schematic cross-sectional model of a magmatic-hydrothermal system ........................15
Figure. 4. Schematic cross-sectional diagram illustrating the fluid pathways and hydrothermal
characteristics for the different IOCG genetic models ..................................................................24
Figure. 5. The Great Bear Magmatic Zone (GBMZ). ...................................................................29
Figure. 6. Stratigraphic column of the Hottah terrane–Great Bear volcano-plutonic continuum .33
Figure. 7. Tectono-magmatic models for the evolution of the Wopmay Orogen ......................... 34
Figure. 8. Geology of the Mazenod Lake region ...........................................................................37
Figure. 9. Geology of Mazenod Lake area, NWT. ........................................................................38
Figure. 10. Geology of Dan Island and surrounding area, Mazenod Lake region, NWT..............39
Figure. 11. Geology of the Bea area, south of Mazenod Lake, NWT. ..........................................40
Figure. 12. Outcrop photographs of selected intrusive rocks discussed in this thesis ...................42
Figure. 13. Outcrop photographs of volcanic assemblage rocks discussed in this thesis ..............46
Figure. 14. Outcrop photographs of several different facies and textures of volcaniclastic
sediments (VS) that are discussed in this thesis.............................................................................47
Figure. 15. Outcrop photographs of hydrothermal alteration types discussed in this thesis .........53
Figure. 16. Geo-eye 1 satellite image of the Mazenod Lake region ..............................................64
Figure. 17. Close-up image of Net Ridge, Mazenod Lake region, NWT ......................................65
Figure. 18. Magnetic vertical gradient (MVG) data layered over Geoeye-1 satellite image.........67
Figure. 19. Structural diagrams compiled from field work measurements....................................68
Figure. 20. Digital elevation data and lake/river outlines on Geoeye-1 satellite image ................69
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Figure. 21. Mazenod Lake area satellite image lineament interpretation ......................................71
Figure. 22. Lineaments drawn on Net Ridge, Mazenod Lake region, NWT…. ......................... 72
Figure. 23. Magnetic vertical gradient (MVG) data lineament interpretation layered over
Geoeye-1 satellite image ................................................................................................................74
Figure. 24. Kernel density model showing the population density of lineaments per square
kilometer, derived from the satellite image. ..................................................................................77
Figure. 25. Kernel density model showing the population density of lineaments per square
kilometer, derived from the MVG data..........................................................................................78
Figure. 26. Kernel density model showing the population density of lineament intersections per
square kilometer, derived from the MVG data ..............................................................................80
Figure. 27. Spatial locations of geochemical data points...............................................................82
Figure. 28. Volcanic rock geochemical discrimination diagrams..................................................88
Figure. 29. Geochemical discrimination of rocks from the Mazenod Lake area ...........................89
Figure. 30.Granite geochemical discrimination diagrams .............................................................91
Figure. 31. Binary diagrams of typical immobile elements and zircon geochemical data ............93
Figure. 32. Binary diagrams of major element oxides and zircon geochemical data ....................94
Figure. 33. Location map showing where lithogeochemical samples originated that have been
mass balance analyzed ...................................................................................................................96
Figs. 34a, b. Isocon diagrams.........................................................................................................98
Figure. 35a, b. Isocon diagrams .....................................................................................................98
Figure. 36a, b. Isocon diagrams ...................................................................................................101
Figure. 37a, b. Isocon diagrams ...................................................................................................101
Figure. 38. Graph of calculated concentration changes for MA-altered samples ........................104

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Figure. 39. Graph of calculated concentration changes for potassic altered ...............................106
Figure. 40. Graph of calculated concentration changes for samples tourmaline altered .............107
Figure. 41. Graph of calculated concentration changes for samples propylitic altered ...............109
Figure. 42. Graph of calculated concentration changes for samples hematite altered .................110
Figure. 43. Graph of calculated concentration changes for samples silicified ............................112
Figure. 44. Bubble plot map of sodium enrichment intensity......................................................116
Figure. 45. Interpolation of sodium enrichment intensity............................................................117
Figure. 46. Bubble plot map of iron enrichment intensity. ..........................................................118
Figure. 47. Interpolation of iron enrichment intensity .................................................................119
Figure. 48. Bubble plot map of Ca-Fe enrichment intensity........................................................121
Figure. 49. Interpolation of Ca-Fe enrichment intensity..............................................................122
Figure. 50. Bubble plot map of potassic alteration intensity .......................................................124
Figure. 51. Interpolation of potassium alteration intensity ..........................................................125
Figure. 52. Bubble plot map of potassic alteration intensity .......................................................126
Figure. 53. Interpolation of potassium alteration intensity ..........................................................127
Figure. 54. Bubble plot map of silica enrichment intensity .........................................................130
Figure. 55. Interpolation of silica enrichment intensity ...............................................................131
Figure. 56. Satellite image and aerial phot of Net Ridge giant quartz vein .................................134
Figure. 57. Interpretation of major structures in the Mazenod Lake region ................................136
Figure. 58. Locations of measurement for estimated lateral displacements of major faults .......137
Figure. 59. Map of tectonic blocks shown on MVG data ............................................................140
Figure. 60. Potassic RAI I contours overlain on Dan Island .......................................................149
Figure. 61. Thin section images of selected analyzed samples....................................................184

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Figure. 62. Backscattered electron microprobe images of selected sites in sample 98197 .........192
Figure. 63. Distribution of silver concentrations in the Mazenod Lake region ...........................205
Figure. 64. Distribution of arsenic concentrations in the Mazenod Lake region .........................206
Figure. 65. Distribution of gold concentrations in the Mazenod Lake region .............................207
Figure. 66. Distribution of bismuth concentrations in the Mazenod Lake region .......................208
Figure. 67. Distribution of copper concentrations in the Mazenod Lake region .........................209
Figure. 68. Distribution of cobalt concentrations in the Mazenod Lake region ..........................210
Figure. 69. Distribution of mercury concentrations in the Mazenod Lake region .......................211
Figure. 70. Distribution of lanthanum concentrations in the Mazenod Lake region ...................212
Figure. 71. Distribution of molybdenum concentrations in the Mazenod Lake region ...............213
Figure. 72. Distribution of tungsten concentrations in the Mazenod Lake region ......................214
Figure. 73. Distribution of uranium concentrations in the Mazenod Lake region .......................215

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Chapter I: Introduction
This thesis is a geological, geochemical and structural investigation of the Mazenod Lake
volcano-plutonic suite, located in the southern Great Bear Magmatic Zone (GBMZ), Northwest
Territories (NWT) (Fig. 1). The Mazenod Lake region is an exceptional example of a wellexposed interior system of a magmatic-hydrothermal iron oxide copper-gold (MH-IOCG)
complex. This makes it an excellent area for detailed investigations with an aim of gaining an
improved understanding of an MH-IOCG type system.
Mazenod Lake is within the southern portion of the GBMZ, between two regionally
important IOCG deposits. The Proterozoic NICO gold-cobalt-bismuth-copper deposit is located
~8 km to the southeast and Sue-Dianne copper-gold-silver deposit ~4 km to the north (Goad et
al., 2000; Mumin et al., 2010). Both deposits are positioned within the same continental volcanic
belt that also includes the Mazenod project area.
Generous support by BFR Copper and Gold Inc. (BFR) and Dawn Zhou, president of
BFR, facilitated this work with the provision of research funding, scholarships, geological
information, satellite imagery, geophysical and geochemical data. In addition, BFR also provided
the opportunity to spend nearly three months at Mazenod Lake with the purpose of carrying out
detailed mapping and geological sampling. The fieldwork was carried out by Scott Ryan and
John Shmyr, Kyle Reid, Dr. H. Mumin, Rashid Mumin, Shane Gleeson and Mark Hamilton.
Fieldwork forms the foundation for subsequent analyses and interpretations presented in this
thesis. Compilation, analytical work and interpretations were completed at the Brandon
University Laboratory for Applied Research in Resource Geology and the Brandon University
Micro-Analytical Facility.

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The thesis is presented in 9 chapters, beginning with an introduction and historical outline
of work accomplished in the Mazenod Lake area, followed by a synthesis of current knowledge
on IOCGs. The next chapters cover the detailed work completed for this project with an in depth
look at geology, structure and geochemistry. The final chapters summarize and discuss, then
interpret the results of the research. The thesis ends with a set of conclusions and
recommendations.

Location, Physiography and Climate
Mazenod Lake is located in the Northwest Territories approximately 185 km to the
northwest of Yellowknife (Fig. 1). The lake lies along the drainage path of the Marian River
within the Mackenzie District. Nearby communities include Gam’et’i and Wha’t’I, which are
respectively ~48 km north and ~63 km south of the study area. Both communities are members
of the Tlicho First Nations government, which has title to ~39,000 km2 of land between Great
Slave Lake and Great Bear Lake, including both surface and subsurface rights (Indian and
Northern Affairs Canada, 2003).
Year-round access to this area is limited to float planes or helicopters. During the winter
months, the federal government maintains an ice road that runs directly across Mazenod Lake.
The Northwest Territories and Tłı̨ chǫ governments have made some progress with discussions to
develop an all-weather road to service the nearby Tłı̨ chǫ First Nations communities. The planned
94-km road would lead to Gam’et’i to the north of Mazenod Lake and would likely replace
portions of the existing ice road. The proposed road would also run within close proximity to
Mazenod Lake and the Mazenod project area.
Climate within the study region is generally temperate during the relatively short summer
months (average of approximately 18°C in July), and bitterly cold during the winter (average of
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approximately -27°C in January, Environment Canada, 2015). This region is within the
physiographic division of Canada known as the Canadian Shield, which is generally covered by
boreal forest that includes common deciduous and coniferous trees such as spruce, pine, alder,
willow and birch. Undergrowth has extensive moss cover in the swampy areas. Labrador tea
plants are present throughout most of the study area wherever there is available soil and/or moss
cover. Lichen growth on rock is very common although not ubiquitous in large part due to a
recent forest fire that removed much of the vegetation from a large portion of the study area.
The study region has a moderate to rugged relief of between 195 to 350 meters above sea
level. Mazenod Lake is relatively shallow with few isolated deep areas. Bathymetric mapping
performed during field operations indicated a depth of less than 5 feet to greater than 350 feet,
and an estimated average of approximately 35 - 40 feet of water.
Outcrops are generally well exposed on islands and terrain surrounding Mazenod Lake.
Further from the lake, muskeg and bog become more common, while outcrops become scarce
and difficult to access. Approximately 80% of the study area is covered by swamp and water,
while approximately 20% contains exposed outcrop. Less than half of the exposed outcrop
within the study region has undergone ground-based studies described in this work.
The study area has been divided into two distinct physiographic and geologic zones of
interest which are often discussed separately in this thesis (Fig. 2). These zones are referred to as
the Mazenod and Bea areas, which comprise the northern two thirds of the project area and the
southern zone respectively. Both areas were named after the dominant lakes of their respective
regions. A finger of Paleozoic sedimentary cover partially separates these two areas.
The coordinate system used to reference several of the maps displayed in this thesis is
UTM (Universal Transverse Mercator) NAD (North American Datum) 1983, zone 11. Some

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maps constructed as part of this research also include location reference by Latitude and
Longitude. The center of Mazenod Lake is located at geographic coordinates 63°40’N, 117°1’W,
while most field work took place in the areas outlined in Figure 2.

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Fig. 1. Regional location of the Mazenod Project, NWT, after Mumin et al. (2014).

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NWT

Fig. 2. Geographic location of the study region within the Northwest Territories. Areas where
field work took place are highlighted with red squares.

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Chapter II: Previous Work in the Mazenod Lake Area
The Geological Survey of Canada (GSC) has conducted numerous studies in the
Mazenod Lake area, from reconnaissance mapping by Lord (1942) and McGlynn (1979) to the
more recent metallogenic surveys by Sunil Gandhi (Gandhi, 1994; Gandhi et al., 1996; 2001).
The most recent work by the GSC was accomplished due in large part to a surge in interest of
IOCG deposits that took place in the 90s, a consequence of recognition of the relatively new
class of mineral deposits. The studies conducted have resulted in numerous publications
including those reviewing the geology at Mazenod Lake and surrounding regions as well as a
regional 1:50000-scale map produced by Gandhi (2013).
Despite the work completed by the GSC, the Mazenod Lake area has experienced rather
limited exploration. Noranda originally staked a large part of the area surrounding Mazenod
Lake in 1974. It has since been explored by several independent companies including the
Western Mining Corporation (WMC), Moss Resources in coordination with Xemac Resources,
Alberta Star Mining Corporation and Phelps Dodge Corporation of Canada Limited. Independent
junior exploration company BFR Copper & Gold is the only exploration company presently
performing exploration activities in the area.
Only nine drill holes have been completed within the Mazenod claims, all within a
relatively concentrated area near the eastern perimeter of Mazenod Lake. Phelps Dodge drilled
the most significant holes, up to 266.7 m, with the best results returning 12 m @ 1525 ppm Cu
including 3 m @ 4308 ppm Cu (Kulla, 2004). Highest copper values were hosted in an altered
magnetite-rich meta-sediment.
BFR Copper & Gold Inc. acquired claims previously held by Freeport McMoRan in 2011
and has since performed additional exploration at Mazenod. Exploration activities have included
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geophysical surveys, geophysical modeling, acquisition of high-resolution satellite imagery,
ground reconnaissance, detailed field mapping and a lithogeochemical sampling program. These
activities were carried out in preparation for drilling within the Mazenod Lake region.
Industry and government activities related to the exploration of geology and mineral
potential within the study region are summarized further in Table 1:

TABLE 1. History of work completed within vicinity of Mazenod Lake

Year
1942

Company / Involved Parties
Geological Survey of Canada
(GSC)

Activity
-Reconnaissance mapping by C. S. Lord1

1974-81

Noranda

-Diamond drilling for uranium in a quartz
vein zone on the east shore of Mazenod
Lake
-Staking and ground exploration with a
focus on the northern part of the property
-Exploration at Nod Hill including mapping,
ground magnetics, induced polarization
(IP), and percussion drilling of 9 holes
-Exploration of Dan Island including
mapping and ground magnetics1 2

1979

Geological Survey of Canada
(GSC)

Reconnaissance mapping by J. McGlynn

1994

Western Mining Corporation
(WMC)

-Staked and completed surface exploration
predominantly on the islands to the
northeast and stream sediment testing (no
anomalies reported)1

1994

Geological Survey of Canada
(GSC)

-Regional metallogenic survey by S. S.
Gandhi

1996

Moss Resources and Xemac
Resources

-Property optioned, completed surface
exploration and diamond drilling of 4
holes1

1996

Geological Survey of Canada
(GSC)

-Regional metallogenic survey by S. S.
Gandhi

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1998

Alberta Star Mining
Corporation

-Acquired 60% interest in the property and
partially completed mapping, prospecting
and ground magnetics of the Bea Lake grid
and re-logging of core at the Nod prospect
before returning claims to WMC1

2001

Geological Survey of Canada
(GSC)

-Regional metallogenic survey by S. S.
Gandhi1

2001-02

Phelps Dodge Corporation of
Canada, Limited

-Reconnaissance, prospecting,
lithogeochemical and soil sampling and
prospect evaluation1
-1150 m of diamond drilling (5 drill holes).
Program cut short due to budget and
weather constraints2

2011- Present

BFR Copper & Gold Inc.

-Mining leases transferred from Freeport
McMoRan Inc. to BFR3
-Geophysical data remodeling by SJ
Geophysics
-Historical compilation of previous work by
Greg Kulla, P.Geo.
-IP-Mag survey on Nod Hill by SJ
Geophysics
-Site prospecting by BFR geologists and
consulting geologist Dr. Hamid Mumin
-Fixed wing magnetic gradiometer,
radiometric & VLF EM survey flown by
Goldak Airborne Surveys
-Undergraduate project identifying
mineralogy, alteration and their
relationships of samples acquired during
site prospecting tour
-1:2000 scale field mapping and
lithogeochemical surveying
-M.Sc. thesis performing geology, structure
and geochemical compilation, analysis and
interpretations
1
(Skanderbeg, 2001); 2(Kulla, 2004); 3(Bender, 2013)

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Chapter III: Iron Oxide Copper-Gold Deposits
Hitzman et al. (1992) was the first to discuss IOCGs as a unique class of deposits with
their own physical and genetic characteristics. These deposits are hydrothermal in origin and are
characterized by enrichments of Fe, Cu ± Au and abundant (< 15 - 20 wt. %) low-Ti
hydrothermal iron oxides. The IOCG group of deposits can also have important concentrations of
Fe, Ag, U, Nb, Co or Bi and rare earth elements (REEs) and may contain anomalous amounts of
Ba, F, P, W, Se, Hg, Te, Sn, Mo and Y. The substantial economic potential makes IOCG
deposits appealing for both research and commercial motives (Hitzman, 2000; Porter, 2000;
Williams et al., 2005, 2010; Skirrow, 2010).
Williams (2010) divided IOCG deposits into a family of related subtypes, the most
important of which are the Magnetite Group (e.g. Candelaria-Chile, Ernest Henry-Australia,
Salobo-Brazil) and Hematite Group (e.g. Olympic Dam-Australia, Prominent Hill-Australia,
Mantoverde-Chile) subtypes. They are characterized by their dominant iron oxide and are known
as IOCG deposits sensu stricto. The next most important sub-group are the iron-oxide apatite
(IOA) deposits (e.g. Kiruna-Sweden, Port Radium-Canada, Pea Ridge-USA, El Romeral-Chile),
which is dominated by Na ± Ca alteration and hydrothermal breccias cemented by magnetite,
actinolite and apatite. Table 2 highlights some of the defining characteristics of magmatichydrothermal IOCG deposits (Richards and Mumin, 2013a, b).

Economic Importance
Globally IOCG deposits have a major economic impact, particularly for Fe, Cu, Au, U
and REEs (Williams et al., 2005). They can be a junior or major exploration companies defining
discovery, containing ore bodies hosting deposits of 10s of Mt (e.g. NICO) to >2000 Mt (e.g.
Olympic Dam) of ore (Corriveau et al., 2010). Metal contents on average are relatively moderate
- 10 -

to low compared to some deposit types (e.g. SEDEX, VMS, MVT), but there are exceptions,
such as the Osborne deposit within the Cloncurry district in Australia that in 2008 had a reserve
of 15.2 Mt at 3% Cu and 1.05 g/t Au (Fisher et al., 2008). Probably the most well-known IOCG
deposit is the Olympic Dam (Cu-U-Au) Mesoproterozoic deposit in South Australia, with a
current total measured resource of 1330 Mt at 0.96% Cu, 0.29 kg/t U3O8, 0.40 g.t Au and 2 g/t
Ag (BHP Billiton, 2015 Annual Report, www.bhp.com). The Olympic Dam deposit is the
world’s largest single resource of U and a major global source of Cu and Au (Skirrow et al.,
2007).
Of more immediate importance for the purposes of this thesis are the IOCG deposits that
occur within the GBMZ. Past producing mines include the Echo Bay Mine (Ag-Cu), Eldorado
Mine (U-Ag-Cu-Co-Ni-Pb-Ra-Po), Contact Lake Mine (Ag-U), El Bonanza Mine (Ag), Terra
Mine (Ag), Norex Mine (Ag), Ray Rock Mine (U), Damp Mine (U) and Tatie Mine (U). Closer
to Mazenod Lake and within an 8 km radius are two IOCG-type deposits owned by Fortune
Minerals Limited. South of Mazenod Lake is the NICO deposit that contains combined
underground and open pit proven mineral reserves of 33 Mt at 0.04% Cu, 1.03 g/t gold, 0.11%
Co and 0.14% Bi (Burgess et al., 2014). Only 4 km to the north of Mazenod Lake is the SueDianne deposit which contains an indicated 8.4 Mt resource at 0.8% Cu, 0.07 g/t Au, 3.2 g/t Ag
(Fortune Minerals, 2009). Both deposits are located within the same NNW trending volcanic belt
and hosted within Faber group volcanic rocks.

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TABLE 2. Defining characteristics of magmatic-hydrothermal IOCGs, modified from Richards and
Mumin (2013a, b).

Characteristics
Major metal association

IOCG deposit type
Fe, Cu, Au

Minor metal association

U, REE, Co, Ag

Sulfur content

Low relative to porphyry copper deposits

Common ore mineralogy

Magnetite, hematite, chalcopyrite, bornite, chalcocite

Ore fluid

H2O-CO2-NaCl-KCl-CaCl2 (10-50 wt. % NaCl equivalent)

Oxidation; pH

Oxidized; neutral to mildly acidic, rarely acidic

Source of magmas

Subduction-modified lithosphere

Source of fluid

Alteration geochemistry

Magmatic predominant ± crustal (basin/surface) ±
metamorphic derived
Evolved/subduction modified lithosphere and fluxing from
host rocks
Na-K-Fe-P-Ca-CO2-SiO2-B

High-temperature alteration
mineralogy (<~400°C350°C)
Low-temperature alteration
mineralogy (>~400°C350°C)

Na-rich: Albite, scapolite, amphibole, pyroxene Na-Ca-Ferich: Magnetite, actinolite, apatite, alkali feldspar K-Ferich: K-feldspar, magnetite, biotite, amphibole
K-Fe-Ca-CO2-rich: Hematite, sericite, chlorite, epidote,
carbonate, quartz, phyllic and/or propylitic in some
deposits SiO2-Fe-CO2-rich: Quartz, hematite ± carbonate

Diameter of high-temperature
alteration
Depth of formation

1 to ≥ 7 km (and possibly greater)

Geothermal gradient

Elevated gradient

Regional metamorphism

Low to high grade

Magma composition
Tectonic setting

Calc-alkaline to alkaline; oxidized; mafic to felsic; I or Atype
Distal, back-arc or post-subduction

Kinematic setting

Extension to transtension

Common controls on deposit
formation
Age range

Regional structures, nearby intrusions

Source of metals

Surface to ≥ 5 km

Dominant in Precambrian, but not restrictive to age

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Morphology & Structural Controls
There are many examples of different morphologies for the IOCG clan of deposits.
Deposit examples exist that are stratabound sheets (e.g. Magnitogorsk deposit, Russia; Gandhi,
2003), stockwork zones (e.g. Kwyjibo deposit, Canada; Perreault and Lafrance, 2015), breccias
(e.g. Olympic Dam deposit, Australia; Williams et al., 2005) and disseminated (e.g. Osborne and
Starra deposits, Australia; Williams et al., 2005) varieties, which can be stratiform or discordant.
The various deposits all have their own unique form; however, they are exclusively hydrothermal
replacement and infill deposits where ore and alteration minerals have replaced host rocks and
infilled open spaces hosted in fractures and brecciated rocks.
IOCG deposits universally exhibit strong structural control, a quality that all
hydrothermal deposits share (Williams et al., 2005). Faults, fractures or other permeable
structures make ideal conduits for the flow and spread of fluids necessary to form hydrothermal
ore deposits. Magmas, which provide the heat source and much of the volatiles and metals that is
necessary for mineralization in IOCG deposits, also intrudes along these structural zones. For
these reasons, IOCG deposits are usually found at intersections of major crustal structures, which
typically have a tensional or transtensional component (Richards and Mumin, 2013a, b).
Metal deposition sites include dilational jogs (e.g. Olympic Dam), duplexes, splays on
faults (e.g. Carajas district and Monakoff deposit), en echelon extensional fractures, shear zones,
cavities of folds (e.g. Tennant Creek district) or form from the interactions between differentially
permeable lithologies (Sillitoe, 2003; Williams and Skirrow, 2000; Corriveau et al., 2007).
Consequently, major crustal structures have a direct influence on the formation of deposits on a
regional and local scale. Exploration and research strategies (such as in this study) will therefore
often emphasize the importance of structure.

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Spatial & Geologic Context
With the exception of Antarctica, known IOCG deposits are distributed across all
continents and include representative examples from Archean to Cenozoic age (Barton, 2014).
Their relative economic importance is not partial to any of the locations or ages, which
demonstrates the variety of their geologic setting.
The geology and tectonic setting for IOCG deposits is also quite diverse. IOCG districts
have been located in Precambrian shields, along active orogenic belts and in back-arc and other
post-subduction settings (Williams et al., 2005; Richards and Mumin, 2013b). Where magmatic
associations are recognized, they are typically of calc-alkaline to mildly alkaline character
(Richards and Mumin, 2013a, b). Despite the diversity of tectonic setting, the kinematics of
IOCG deposits tend to demonstrate extensional or in transtensional tectonics within intracratonic
or continental-arc zones. IOCG deposits are often spatially and genetically associated with
epithermal and skarn deposits or mineralization (Mumin et al., 2007, 2010) and those IOCGs
known to have a magmatic-hydrothermal association are similar in many aspects to porphyry-Cu
deposits, notwithstanding distinct and important differences (Mumin et al., 2007, 2010; Richards
and Mumin, 2013a, b).

Hydrothermal Alteration
The most diagnostic hydrothermal alteration indicative of the core of IOCG systems is
alkali-iron enrichment (Na-K-Fe) (Hitzman et al., 1992; Mumin et al., 2007, 2010) (Fig. 3).
Typical alteration zones in IOCG hydrothermal systems generally exhibit progressive alteration
mineral assemblages, from high-temperature, relatively reduced, neutral pH assemblages closest
to the source to progressively distal lower-temperature, oxidized, lower pH assemblages (Mumin

- 14 -

Fig. 3. Schematic cross-sectional model of a magmatic-hydrothermal system that illustrates the
hydrothermal alteration zoning pattern and relationships between S-rich porphyry Cu ± Mo ± Au deposits
and S-poor MH-IOCG deposits (Richards and Mumin, 2013b).

et al., 2007, 2010; Richards and Mumin, 2013a, b). All the typical alteration zones do not
necessarily have to form or may not be preserved after periods of erosion (e.g. Somarin and
Mumin, 2013). Unique alteration types may also evolve that reflect the geologic diversity of their
setting. These hydrothermal systems tend to be spatially extensive, extending to wide zones that
can range from a few meters to 100s of km (Corriveau et al., 2007). Multiple hydrothermal cells
often overlap, which may be difficult to differentiate as they combine alteration types and
effects. The illustration in Figure 3 demonstrates the unique paragenetic sequence of alteration
that is a distinguishing factor in defining IOCGs from other ore-forming systems.

- 15 -

Mass gains and losses in altered host rocks around IOCGs illustrate exchanges in
elemental abundances of most major and minor elements with varying degrees of mobility that
depend upon physio-chemical conditions of mineral formation. The most common whole-rock
composition changes include both additions and depletions in Na, K, Ca, Fe and Si. Changes in
framework silicate mineralogy are the most common observable manifestation, with K-feldspar
± biotite forming in potassic altered areas and albite forming in sodic (albitic) altered zones.
These changes in mineralogy often include tiny inclusions of hematite within the rock which
imparts a characteristic reddish to reddish-brown color, colloquially known as ‘red rock’
alteration (Wenner and Taylor, 1987; Williams, 1994). Fe-enrichment manifests as magnetite in
high-temperature proximal areas and hematite in lower-temperature parts of the system. Silica
enrichment can occur as widespread silicification of host rocks, and /or as distal or late-stage
massive (giant) quartz veins and/or stockworks.
Textural changes may or may not occur during hydrothermal alteration. Pseudomorphic
replacement is a common method of altering mineralogy from one state to another without
completely changing the rock texture. Alteration may also be texturally destructive, with often a
complete change in texture and chemistry of the original host, which makes identifying the
protolith a difficult task. In most instances replacement is spatially selective, and dependent upon
local permeability conditions and available conduits for hydrothermal fluid migration.
One of the important aspects of understanding hydrothermal alteration for exploration of
mineral deposits is its representation of the migration of fluid. Seemingly disparate alteration
effects may in fact be parts of an overall hydrothermal system. For IOCGs, and similar
hydrothermal ore deposits, the alteration zones are obvious expressions of physio-chemical

- 16 -

gradients that can potentially be traced to proximal zones of ore deposition (Corriveau et al.,
2010).
IOCG-type hydrothermal alteration is generally defined in terms of elemental and/or
mineral changes. The major alteration zones common to most IOCG systems are described
below and include: Sodic, magnetite ± actinolite ± apatite (MAA), potassic, phyllic, tourmaline,
carbonate and silicification.
(a) Sodic Alteration
Sodic (or albitic) alteration is known to involve the relative addition of Na to country
rock. Typically, these alteration zones are also found to be regions of element leaching, where
predominantly K and other alkali or alkali earth metals being depleted (Barton, 2014). Sodic
altered rock usually results in host rock that experiences a change in framework silicates, where
feldspars convert to their sodium phase (albite). The alteration can be either texturally destructive
or preservative depending on the host rocks chemistry, intensity of alteration and degree of
stress. Intense sodic alteration may generate albitites, composed of dominantly sodic-rich
plagioclase, which may grade outwards from the source intrusion to a ‘patchy’ albitization.
(Corriveau et al., 2010).
Several authors have associated high-temperature albitic alteration with the cores of
IOCG hydrothermal cells (Corriveau et al., 2010; Richards and Mumin 2013b; Barton, 2014).
Spatially this type of hydrothermal alteration is within the highest temperature zone, proximal to
the heat source (igneous or otherwise). In some (possibly rare) instances it may indicate a source
of abundant Na in the host rocks (e.g. evaporite). While this alteration can be intense due to
proximity of a heat and Na source, it can also be spatially very extensive. Temperatures of

- 17 -

formation are estimated at ~600° to ~400°C (Mumin et al., 2007, 2010; Corriveau et al., 2010;
Mumin and Richards, 2013a; Somarin and Mumin, 2013).
Base and precious metals in the Na-alteration zone can be significantly depleted
(Williams, 1994; Menard, 1995; Barton and Johnson, 1996, 2000; de Jong et al., 1998; Oliver et
al., 2004, 2008; Richards and Mumin, 2013a, b). In contrast to this proximal zone of IOCG
systems, porphyry-Cu hydrothermal systems have potassic cores, commonly associated with
metal enrichments (Sillitoe, 2010); however, Richards and Mumin (2013a, b) have shown that
Na alteration can occur in porphyry systems deep below the potassic core.
(b) Iron Oxide Alterations
High temperature and low temperature varieties of hydrothermal iron oxide alteration are
diagnostic of IOCG systems. Most of the important IOCG deposits are directly associated with
extensive iron oxide enrichment (e.g. Candelaria, Olympic Dam, NICO, Carajas district, Ernest
Henry; Goad et al., 2000; Williams et al., 2005). Typically, mineral exploration efforts often
begin with an application of regional magnetic and gravity surveying to target unique physical
properties associated with iron oxide alteration. Geophysical anomalies that are considered to be
potential zones of iron oxide enrichment are then further inspected for their potential economic
potential. The iron oxide alteration can be subdivided into two distinct categories in recognition
of their predominant mineral characteristics, magnetite-actinolite-apatite (MAA) and hematite.
Magnetite is the high temperature variant of iron oxide and is commonly associated with
actinolite ± apatite ± albite ± K-feldspar minerals (Richards and Mumin, 2013a, b). Texturally
MAA alteration can be coarse grained and massive (e.g. Mag Hill from Somarin and Mumin,
2013), but finer-grained replacements and breccias are also common. The alteration may also
manifest as veins or veinlets.
- 18 -

Like the above discussed sodic alteration, MAA alteration develops in relative proximity
to heat sources. In a schematic model of an MH-IOCG hydrothermal system by Richards and
Mumin (2013b), the MAA alteration is placed sequentially adjacent to sodic alteration
progressing outwards from a potential heat and fluid source intrusion. In a few instances MAA
type alteration has been known to form the wall rock of IOA deposits, such as in the Kiruna
district, and Chilean and Peruvian iron belts, or the wall-rock for magnetite group IOCGs (e.g.
Osborne, Ernest Henry, Salobo deposits) (Williams, 2010).
The lower temperature variant of alteration produced by Fe-saturated hydrothermal fluids
is hematite ± sericite ± chlorite ± carbonate ± quartz. Hematite is a more distal, lower
temperature and more oxidized alteration product, which may form adjacent to or above
magnetite-bearing zones, or instead be a late superposition on magnetite alteration (Skirrow,
2010). Precious and base metals, REEs and/or uranium enrichments have been known to be
concentrated within this alteration zone and can form impressive deposits (e.g. Olympic Dam,
Prominent Hill; Williams et al., 2005). Hematite cemented breccias and stockworks are the
characteristic textural variety these deposits.
(c) Potassic Alteration
K-alteration occurs in both high and low temperature forms in IOCG systems, each with
their own distinct characteristics. A hydrothermal system that evolves beyond sodic alteration
may form a high temperature K-Fe stage that contains potassic ± ferroan minerals (K-feldspar ±
biotite ± magnetite ± amphibole) (Corriveau et al., 2010). This particular type of alteration is
host for mineralization in magnetite-type IOCG deposits such as the Cu-Au deposits ErnestHenry, Salobo, Candelaria, Aittik and NICO. It is also one of the more difficult alteration

- 19 -

assemblages to identify, as both lower temperature varieties and sodic alteration zones can
appear similar in color and texture.
The distal, lower temperature phase of potassic alteration may occur with or be spatially
associated with hydrolytic (acidic) and/or hematite alteration. This phase of alteration is further
from the core of the hydrothermal cell and can extend for several kilometers. The most common
mineral representation of this type of alteration is K-feldspar and hematite, often with sericite
and can include chlorite and/or calcite. Specularite, a course crystalline variety of hematite often
occurs in this alteration zone. Several globally important deposits are constrained within this
alteration zone, including Olympic Dam and Prominent Hill (Williams et al., 2005).
(d) Tourmaline Alteration
Tourmaline alteration is common in some IOCG systems and typically forms the Fe-rich
end member schorl or Mg-rich dravite species of minerals (e.g. Copiapó, Chile; Collins, 2010).
This type of alteration has been linked to emplacement of granitic magmas that are boron-rich or
from boiling-induced boron-rich residual fluid (Pirajno, 2009). Syn-volcanic episodes of
hydrothermal alteration at temperatures of ~300° and 1-3 km depth of a highly saline and boronrich fluid are the optimal conditions to induce tourmaline precipitation. At that temperature and
depth tourmaline alteration is generally distal or intermediate to the core of an IOCG
hydrothermal cell.
(e) Phyllic and other Hydrolytic Alterations
Hydrolytic alteration involves the decomposition of H2O into H+ and OH- ions. The ions
are consumed during reactions with silicate minerals, resulting in phyllosilicate mineral
assemblages including those found in sericite, phyllic (quartz + sericite ± pyrite) and argillic
(clay mineral) alteration zones. In IOCGs the source of H+ ions may be subsolidus reactions
- 20 -

during alkali metasomatism with hydrogen bearing fluids, such as H2O, HCl or H2S. Reactions
result in the transformation of framework silicates to phyllosilicates and may be accompanied
with a release of metal ions into solution.
The acidic alterations are a distal product of IOCG hydrothermal cell development.
Hydrothermal fluids that escape from magmas have an initial neutral to mildly alkaline pH. As
fluids cool, and sulphate in the magmatic fluid dissociates, residual fluids may become enriched
in H+. This results in mildly acidic to acidic pH reactions distal from the source of the
hydrothermal fluid, and typically leads to conversion of feldspar to sericite.
(f) Silicification
Pervasive silica alteration results in replacement of rock material with quartz or silica. It
is the most distal and/or late stage hydrothermal alteration of an IOCG hydrothermal cell and can
extends into the epithermal environment (Hitzman et al., 1992; Richards and Mumin, 2013b;
Somarin and Mumin, 2013). In the GBMZ, widespread stockworks, breccias and silica flooding
(massive quartz replacement) occur along transcurrent faults and other fracture zones. The SueDianne deposit in the southern GBMZ can be traced along the axis of one of these silicified
faults (Camier, 2002). Richards and Mumin (2013b) explain the presence of pervasive quartz as
a result of leached and mobilized silica in a large MH-IOCG system that became soluble during
prograde alteration and subsequently was deposited during retrograde alteration.
(g) Other Associated Alteration Effects
Skarns are common in many large IOCG systems (Hitzman et al., 1992). Formation of a
skarn is not dependent on the presence of an IOCG system and instead is necessitated by the
reaction of hydrothermal fluids, from any high-temperature heat source with carbonate-rich rocks
(Corriveau et al., 2010; Barton, 2014). Skarn mineral assemblages include garnet (grossularite or
- 21 -

andradite) and clinopyroxene (diopside) ± magnetite ± vesuvianite ± epidote ± hornblende ±
sulphides ± scapolite minerals. Although not common, there are examples of IOCG-related
skarn deposits that are mined for copper, such as the Pumpkin Hollow deposit in Nevada
(Schottenfeld, 2012).
IOCG systems have also been identified in proximity and association with epithermal
conditions (Mumin et al., 2010; Somarin and Mumin, 2014). Mumin et al. (2010) and Richards
and Mumin (2013b) suggest that epithermal style mineralization and alteration are part of the
expected normal magmatic-hydrothermal IOCG system. They have cited spatial and temporal
relationships within the GBMZ and elsewhere as evidence. Epithermal style mineralization is
commonly characterized by quartz, quartz-hematite and quartz-hematite-carbonate dominant
mineral assemblages in near-surface veins, breccias and stockworks.

Genesis
Several distinct and current hypotheses on the genetic development of IOCG
hydrothermal systems have been discussed in modern literature (Hitzman, 2000; Pollard, 2000;
Williams and Skirrow, 2000; Barton and Johnson, 2004; Richards and Mumin, 2013a, b). In
large part, the differences in origin of each deposit type are due to their geologic diversity
(Williams, 2010). Most genetic hypotheses include the association of an igneous (magmatic)
source; however, as the intrusions are not always visually apparent and/or spatially close to the
hydrothermal system in question, some researchers have proposed several other ideas. Three
models are predominant in the literature for characterizing IOCGs based on principal fluid
sources, and they can be grouped into two genetic families: magmatic and non-magmatic fluid
sources. Both fluid types are relatively saline, sulfur deficient, neutral pH and oxidized;

- 22 -

however, there are several distinct possibilities as to where the fluid came from and how it
travelled. The different possibilities are explained further below:
(1) Magmatic-hydrothermal model: The first model and most widely accepted considers a
magmatic-hydrothermal source of fluids as the key source and transport mechanism for
enrichment of metals and elements that alter and mineralize country rocks (Hauck, 1990;
Pollard, 2000, 2006; Groves and Vielreicher, 2001; Williams et al., 2001; Sillitoe, 2003;
Mumin et al., 2007; 2010; Richards and Mumin, 2013a, b) (Fig. 4). This theory suggests
that hot, saline, metal bearing and relatively sulphur poor fluids are exsolved from a
cooling, crystallizing magma in the subvolcanic environment. Volatiles such as H2O,
CO2, H2S, B become more enriched in the magma and derived fluids as it solidifies,
fractionates and partitions. When the melt reaches saturation of volatile components
exsolution occurs and many metals preferentially partition into the fluid fraction.
Structural weaknesses in the surrounding country rock then act as conduits through which
the volatiles migrate. The fluid cools and reacts with the host rock through which it
permeates, leaching, transporting and depositing various metals in different parts of the
system. This model is considered to be the best fit for GBMZ IOCG deposits, as well as
many others worldwide (Richards and Mumin, 2013b).
(2) Basin/surface derived fluids model: In this model saline fluids are derived from an
evaporitic source, i.e. coeval or older brine source (Barton and Johnson, 1996, 2000;
Haynes et al., 1995, Haynes, 2000). Evaporites that supply NaCl have been used in
literature to explain the abundance of Na wall rock alteration or Cl-bearing silicates such
as scapolite. Convection of fluids in this model is considered to be driven by an igneous
heat source or other crustal heat source, and in part by the density of the brines.

- 23 -

Fig. 4. Schematic cross-sectional diagram illustrating the fluid pathways and hydrothermal
characteristics for the different IOCG genetic models (Richards and Mumin, 2013b).

Proponents of the model cite proximity of alteration to evaporite rocks in order to explain
a high chloride/sulphur ratio, as well as a lack of evidence for a proximal intrusion;
however, for many well documented IOCGs there is an unmistakable association with
subvolcanic intrusions. Examples include the IOCGs located within the GBMZ (Richards
and Mumin, 2013a, b) or the Gawler craton (Williams et al., 2005). In at least some
IOCG settings (again the GBMZ) there is a complete lack of evidence for any nearby
evaporites (Barton and Johnson, 1996).
(3) Metamorphic-hydrothermal fluids model: The primary source of fluid in this model is
metamorphic derived fluids, where fluids originated from dehydration, decarbonation and
desulphidation reactions of hydrous, carbonate and sulphur-bearing minerals (Oreskes
and Einaudi, 1992; Williams, 1994; de Jong et al., 1998; Hitzman, 2000; Pollard, 2000).
There is not a necessary connection to an igneous source. Barton (2014) lists a number of
- 24 -

possible examples of IOCGs that may be metamorphic-hosted systems that may fit within
this model including hydrothermal systems from Cloncurry and Tennant Creek districts.
Hunt et al. (2007) explains the Wernecke breccias in the Yukon Territory as metamorphic
driven IOCG systems. Alteration that occurs as a result of migrating fluid in this model
reflects the chemical composition of the fluid source, which can include any regionally
metamorphosed rocks. Authors that propose metamorphism as the dominant source of
fluid in an IOCG system suggest there may be some mixing of fluids with a magmatic,
basinal brine source or both (Williams, 1994; Hitzman, 2000; Barton and Johnson, 2004;
Hunt et al., 2007).
Whatever the primary source of fluid, most investigators present evidence of fluid mixing
in many IOCG systems as a critical mechanism for metal precipitation (Oreskes and Einaudi,
1992; Baker, 1998; Requia and Fontbote, 2000; Marschik and Fontbote, 2001; Ullrich et al.,
2001; Mark et al., 2006; Davidson et al., 2007; Kendrick et al., 2008; Richards and Mumin,
2013b; Somarin and Mumin, 2014). The essential concept behind fluid mixing is that formation
of an IOCG deposit involves the interaction of two or more different fluids. In these situations,
lower temperature, oxidized fluids (most likely meteoric) interact with hotter, saline fluids
(basinal brine or more likely magmatic) which creates conditions suitable for metal precipitation
(Reeve et al, 1990; Haynes et al., 1995; Hayward and Skirrow, 2010; Skirrow 2010).
Richards and Mumin (2013a, b) convincingly suggest that the deficiency of sulfur in
IOCG deposits and source fluids can be explained by a secular variation in oceanic sulfate
content going back in geologic time. The S2- anion of sulphide minerals in porphyry magmatic
hydrothermal systems is known to have been sourced from seawater sulphate, which is
scavenged by arc magmas following subduction and devolatization of the oceanic lithosphere (de

- 25 -

Hoog et al., 2001; Wallace and Edmonds, 2011). Subduction of the oceanic lithosphere into the
mantle includes significant amounts of H2O, yet very low concentrations of sulfate during the
Proterozoic and Archean because of a lack of sulfate content in the ocean prior to oxygenation of
the atmosphere (Prouteau and Scaillet, 2013). During subduction, the slab underwent
devolatization reactions under progressively higher temperature and pressure conditions,
fluidizing the overlying mantle wedge and helping to initiate mantle melting and formation of arc
magmas. Interaction of the mantle melt with the base of the crust generated evolved, hydrous,
oxidized, calc-alkaline magmas that were sulfate-deficient during the Proterozoic and Archean,
and sulfate-rich during the Phanerozoic (Richards, 2009; Mumin and Richards, 2012, 2013;
Richards and Mumin, 2013a, b). The paucity of sulphate explains the predominance of IOCGs in
the Precambrian, while abundant sulphate during the Phanerozoic can explain the predominance
of porphyry Cu deposits in the younger rocks. Those IOCG deposits formed in the Phanerozoic
(such as the Mesozoic Mantoverde deposit) that also lack significant sulfur content are explained
as a result of magmas generated from partial melting of relatively S-poor asthenospheric or
subduction-modified lithospheric sources linked to periods of deep ocean anoxia (Richards and
Mumin, 2013a, b).
The source of metals in IOCG systems is another debated topic, because of the range of
possible sources. The most common explanation is that metals are directly sourced from the
magma (Pollard, 2000; Sillitoe, 2003). Fluids derived from magma can contain relatively high
concentrations of metals through preferential metal partitioning into the fluid phase (although the
absolute concentration of metals is actually quite low) (Pirajno, 2009). Another source of
potential metals includes elements leached directly from country rock during wall-rock
interactions with hydrothermal fluids (Richards and Mumin, 2013b). Hot reactive fluid is capable

- 26 -

of, leaching, mobilizing and concentrating metal in country rock during migration of fluid in a
hydrothermal system. All alteration zones in IOCG hydrothermal systems experience varying
degrees of metal leaching, enrichment and redistribution.
Research is ongoing to explain the genesis of IOCGs. This thesis attempts to contribute to
our growing understanding of the IOCG deposit type by updating our current knowledge on the
geology, structure and geochemical relationships, characteristics and constraints, with a focus on
the Mazenod Lake region in the southern GBMZ.

- 27 -

Chapter IV: Regional Geology and Tectonic Setting of the GBMZ
The GBMZ forms the western segment of the Wopmay orogen and is a regional
subdivision of the Proterozoic Bear Province of the Canadian Shield, Northwest Territories,
Canada (Fig. 1). Volcanic, plutonic and sedimentary rocks that comprise the Wopmay orogen
were developed or emplaced during the time period between 1970 to 1890 Ma (Gandhi et al.,
2001). Within the Wopmay orogen there are several divisions separated by similar rocks and
tectonic significance. From east to west these divisions include the Coronation margin, Calderian
foredeep, Turmoil Klippe and the focus for this investigation, the Great Bear magmatic zone
(GBMZ) (Hildebrand et al., 2010; Gandhi, 2013; Mumin et al., 2014). The western edge of the
GBMZ is bounded by the Hottah Terrane continental volcanic arc and the eastern border is
bounded by the Slave craton.
The GBMZ is a north-south trending continental magmatic belt. The belt is exposed for a
length of ~450-km and up to ~100-km wide, that is essentially parallel to the western margin of
the Slave craton. For another approximately 500-km to the southwest and 300-km north-west,
the volcanic belt extends beneath a relatively thin layer of Paleozoic cover (Coles et al., 1976;
Hildebrand and Bowring, 1984; Hoffman, 1987; Hildebrand et al., 2010). Previous investigators
have considered the GBMZ to be a typical analogue for an Andean-type continental magmatic
terrane (Hildebrand et al., 1987). Volcanism within the belt is known to have occurred over a
relatively short period of time with continental volcanism and associated plutonism dated at
~1875 to 1840 Ma (Hoffman and Bowring, 1984; Bowring, 1985; Bowring and Grotzinger,
1992; Gandhi et al., 2001; Ootes et al., 2015).

- 28 -

Mazenod Lake

Fig. 5. The Great Bear Magmatic Zone (GBMZ) is the western subdivision of the Wopmay
orogen (Hoffman and Hall, 1993).

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GBMZ stratigraphy is comprised of several supracrustal groups of volcanic rocks
categorized as the McTavish Supergroup. Unconformities separate the McTavish Supergroup
into the Labine, Dumas, Faber and Sloan volcanic groups (Gandhi et al., 2001; Hildebrand et al.,
2010; Ootes et al., 2015). The northern Labine, Sloan and Dumas groups range up to 10 km
thick. The southern Faber group rocks are made of ~5 km thick layers of volcanic assemblages,
sediments and intrusive rocks.
Oldest of the volcanic assemblages is the LaBine Group, which is exposed along the
western flank of the GBMZ (Fig. 2). An unconformity divides the LaBine Group from the
metavolcanic and metasedimentary rocks that make up the Hottah terrane. The Labine volcanic
group consists primarily of basalt and bedded tuff at the base of the stratigraphy and andesite in
the upper units. Exposed along the east margin of the GBMZ near the Medial Zone (aka
Wopmay Fault Zone) is the Dumas group. Relatively coeval to the LaBine Group, the Dumas
Group contains alternations of mafic to intermediate rocks, felsic ignimbrites and flows as well
as autochthonous sediments. The central area of the GBMZ contains the Sloan Group of rocks
which is the youngest supracrustal sequence in the GBMZ and unconformably separated from
the LaBine Group. Sloan group stratigraphy comprises dacite, rhyodacite and rhyolite flows and
ignimbrites along with relatively small amounts of andesitic lava flows. Complex calderas,
remnants of andesitic stratovolcanoes and associated subvolcanic diorite plutons have been
mapped by investigators extensively within the Sloan Group (Hildebrand, 1982; Mumin et al.,
2014). The Faber Group is located in the southern GBMZ and contains the Mazenod Lake area,
which is the focus of this investigation. Faber Group lithology consists primarily of andesitic
type volcanic and volcaniclastic rocks but ranges from basaltic andesites to rhyodacite
ignimbrites along with associated flows, high level intrusions and autochthonous volcanic

- 30 -

sediments. Gandhi et al. (2001) determined the age of the Faber Group to be ~1865 Ma - roughly
equivalent in age to both the LaBine and Dumas Groups. A chronostratigraphic column
demonstrating the age relationships of the aforementioned geology is illustrated in Figure 6.
One of the last major events in the GBMZ was post-volcanic plutonism at about 18661840 Ma (Hoffman and Bowring, 1984, Gandhi et al, 2001). At this time period, the GBMZ was
intruded by calc-alkaline to alkaline plutons across the length of the magmatic zone (Hoffman
and Bowring 1984; Bowring, 1985; Hildebrand et al., 2010). These intrusions are extensive and
occur as either plug-like bodies such as the Faber Lake rapakivi granite (~ca. 1856 Ma) or long
tabular intermediate to felsic intrusions such as the Marian River batholith (~ca. 1866 Ma;
Gandhi et al., 2001). These intrusions are often coarse-grained, massive and monotonously
homogeneous, but often with differentiated marginal phases (Mumin et al., 2007). The granitic
plutons include a compositional range of diorite, granodiorite, monzogranite or syenogranite that
formed both concordant and discordant to the north-westerly trend of the volcanic belts
(Hildebrand et al., 2010; Mumin et al., 2014). Largest of these intrusions is the Marian River
batholith, a combination of undifferentiated intrusions that engulf Faber Group volcanic rocks.
This giant pluton fences in the Faber Group on the east and west and is considered by some
experts whom have worked in the area to be the source intrusion for the volcanic assemblages
(Goad et al., 2000; Mumin et al., 2007). Coeval to the above intrusions, a sequence of small
diorite to microdiorite dykes intruded into the GBMZ. The southern portion of the GBMZ dykes
generally intruded lithology concurrent to northeast trending transcurrent faults and sometimes
filled existing fault structures (Gandhi et al., 2001).
Although not of major relevance to this thesis because the Hottah terrane pre-dates the
volcanic and sedimentary rocks of the GBMZ, the Hottah rocks have importance to this

- 31 -

discussion because they constrain the evolution of the magmatic zone. Prior to the extrusion of
GBMZ volcanic supracrustal rocks a sedimentary sequence was emplaced on top of the Hottah
terrane basement rock (Gandhi et al., 2001, Gandhi, 2013). This now metasedimentary group
was first named by Gandhi et al. (2001) as the Treasure Lake Group. Metamorphic grade and
deformation of this group increases in intensity towards the Medial Zone to the point of upper
greenschist facies. The Hottah terrane is generally believed to form the basement rocks of the
GBMZ. Despite the general consensus, basement rocks for the Treasure Lake Group have not
been observed at surface in the southern GBMZ. The Hottah terrane that is exposed at surface
has been age dated at ca. 2.5 – 2.0 Ga (Ootes et al., 2015). The terrane is mostly considered by
experts working in the area to be a continental magmatic arc comprising calc-alkaline volcanoplutonic rocks with associated volcanic sediments and intrusions (Hildebrand et al., 1987;
Clowes, 1997). Recent chronostratigraphic work and interpretations by Ootes et al. (2015) has
indicated that the Hottah rocks migrated from the south of its current position due to extensiondriven transtensional shearing (i.e. terrane translation). This notion contrasts previous widely
used models advocating the Hottah terrane was a microcontinent accreted to the Slave craton and
formed over a west-dipping subduction of the Coronation ocean crust (Hoffman et al., 2011).

Structure and Tectonics
The GBMZ is separated from the Coronation margin by a major crustal linear feature
called the Wopmay fault zone, or in more recent literature it is referred to as the Medial Zone
(Hildebrand et al., 1990). The Medial Zone is a major area of crustal deformation where rocks
have been folded and faulted along a northern axial trace (Hildebrand et al., 1987; Hildebrand
and Bowring, 1988; Hayward and Corriveau, 2014). Hildebrand et al. (1990) suggested the fault
zone formed due to an oblique angle of subduction and subsequent tectonic shifting along a
- 32 -

Focus area

Fig. 6. Stratigraphic column of the Hottah terrane – Great Bear volcano-plutonic continuum (no vertical
scale implied). (Ootes et al., 2015).

horizontal plane (Fig. 7). Another more recent theory included the possibility that the Medial
Zone is a result of translation along a horizontal plane; essentially large-scale strike-slip
movement, similar to the San Andreas Fault zone (Ootes et al., 2015).

- 33 -

Sometime after the GBMZ
formed a regional set of NE-SW trending
right-lateral transcurrent faults with kmscale strike-slip displacements offset and
segmented the entirety of the continental
magmatic belt. These prominent linear
physiographic features are regional
structural distortions that have been well
defined by magnetic depletion,
topography, and field geology work
(Gandhi et al., 2001; Mumin et al., 2014;
Hayward and Corriveau, 2014). The
transcurrent right lateral faults appear to
mostly terminate at or near the Medial
Zone on the eastern side of the GBMZ.
Fig. 7. Tectono-magmatic models for the evolution of
the Wopmay Orogen and the GBMZ (after Ootes et
al., 2015). (a) Accretion of the exotic Hottah terrane to
the western Slave craton ca. 1880 Ma., subsequent arc
magmatism resulting from eastward-directed
subduction and formation of the GBMZ. (b) Back-arc
basin formation and magmatism along a convergent
plate boundary ca. 1940-1885 Ma. HIS, Hepburn
intrusive suite; MIZ, metamorphic internal zone; TK,
Turmoil klippe; WFZ, Wopmay fault zone.

Interpretations of regional magnetic
variance also indicate that the
transcurrent faults extend under Paleozoic
cover past the western edge of the GBMZ
to an unknown limit. Research as to the

cause of why the major crustal breaks formed has included the suggestion that they are a result of
an eastward directed terminal terrane collision with the Hottah terrane by the Nahanni-Fort
Simpson terranes (Hayward and Corriveau, 2014). Not supporting this hypothesis, Ootes et al.

- 34 -

(2015) pointed out that brittle deformation actually post-dates the Nahanni terrane emplacement,
specifically referring to the major dextral transcurrent McDonald fault. In a different
investigation of the GBMZ by Mumin et al. (2014) a suggestion was made that the transcurrent
faulting was likely coeval to Great Bear volcanism. This proposal advocated that transcurrent
faulting was a result of, or re-activated by pull-apart domains formed during a NE-SW oriented
extension phase. While evidence of synvolcanic and post-volcanic faulting within the GBMZ has
been discussed in literature there is no conclusive evidence to point to a single tectonic precursor
event. At present, most experts working in the Great Bear agree that pre-volcanic tectonic
activity is related to east-verging subduction along the western margin of the Slave craton
(Hildebrand, 1990; Mumin et al., 2014).

- 35 -

Chapter V: Geology of the Mazenod Lake Region
Throughout this chapter are summary descriptions of the Mazenod Lake area lithology,
hydrothermal alteration and mineralization. The observations described herein are based on 2013
field operations supported with an analysis of lithogeochemical data, remotely sensed imagery,
and past reports that discuss the geology of the region (Gandhi et al., 2001, Skanderbeg, 2001;
Kulla, 2004; Gandhi, 2013). The following maps included in this chapter illustrate interpretations
of the geology described herein; including: Geology of the Mazenod Lake Region (Fig. 8),
Geology of the Mazenod Lake Area (Fig. 9), Geology of Dan Island (Fig. 10) and Geology of the
Bea Area (Fig. 11).

Local Geologic Setting
Geology in the Mazenod Lake area (Figs. 8-11) consists of predominantly ca. 1.865 Ga
felsic to intermediate calc-alkaline volcanic rocks of the Faber Group. These volcanic rocks
include numerous flows, tuffs, agglomerates and breccias (hydrothermal and volcaniclastic). The
volcanic belt consists of lithology arranged in a predominantly NNW curvilinear orientation,
constrained from the east and west within a suite of extensive coeval intrusive rocks. These
plutonic rocks are compositionally diverse and typically range from granite to monzonite
(Gandhi et al. 2001; Gandhi, 2013). Autochthonous sediments are conformable with the volcanic
belt, while Paleozoic allochthonous sedimentary rocks are discordant, overlying the volcanic belt
along an unconformity. Lithology from the Faber Group encompass a significant proportion of
the study area, but also extends to greater than 16 km north along the Kemaz fault (Mar fault of
Camier, 2002 and Mumin et al., 2014) and another approximately 17 km southeast. The
stratigraphic group is subdivided into several volcanic assemblages of similar chemical
composition and mineralogy. Some volcanic assemblages that have been previously included in
- 36 -

the Faber Group stratigraphy are located outside of the study area (Gandhi et al., 2001), which
are not described in this thesis.
Several new rock units have been identified because of field work performed as part of
this thesis project. The newly recognized units have necessitated some new nomenclature for the
stratigraphy, described in the following sub-sections. An attempt was made in this thesis to
remain consistent with previous research completed on the Mazenod Lake region (Hetu et al.,
1994; Gandhi et al., 2001; Camier, 2002; Gandhi et al., 2014; Mumin et al., 2014).
Despite the detailed nature of the 2013 field mapping, some uncertainties remain
regarding the stratigraphy. There were several isolated areas that could not be covered in the time
permitted or were not directly accessible.

Paleozoic Sediments
Paleozoic sediments (PC, Figs. 8, 9) cover a significant proportion of the project area.
The sediments comprise a relatively thin (< 100 m) sub-horizontal sequence of sandstones,
conglomerates, argillaceous sediments and dolomitic rocks (Gandhi, 2013). Previous discussions
by Gandhi (2013) described the sediments as a Cambrian marine transgression over the Great
Bear and Great Slave Lakes region. Sedimentary units are considered undivided in this work,
because they were not mapped in detail and they are not of significant importance to this
investigation.

Great Bear Intrusive Rocks
Gandhi et al. (2001) succinctly described the intrusions of the Mazenod Lake area (Fig.
12), some of which is expanded upon in this report. The medium to coarse grained plutonic rocks
are calc-alkaline, texturally massive, spatially extensive and usually have an orange color on

- 41 -

501524E, 7064185N

502566E, 7064775N

502402E, 7064257N

503030E, 7063195N

503496E, 7064925N

Microdiorite
Dyke

Fig. 12. Outcrop photographs of selected intrusive rocks discussed in this thesis: (a) HM284:
Coarse grained monzogranite (SM) on the north side of NET ridge, (b) HM062: Porphyritic
monzodiorite (MD) with distinctive ‘white’ feldspars and mafic (pyroxenes?) minerals located on
the south side of Dan Island, (c) SR227: Microdiorite dyke that has penetrated the older quartz
monzodiorite (SM) from the NE edge of NET ridge, (d) JS097: Porphyritic monzodiorite (MD),
typical orange hue to the rocks found surrounding Mazenod Lake, (e) HM005: Microdiorite dyke
that has penetrated a andesite crystal tuff ignimbrite. Reference system for coordinate data is UTM
NAD83 zone 11.

- 42 -

weathered surfaces that contrasts well with the surrounding rocks. The intrusions have a
compositional range that includes granite, granodiorite, monzogranite and quartz monzonite.
Spatially and temporally, these intrusions surround, cut across and intrude into the volcanic
assemblages.
At least one significant high-level (sub-volcanic) monzodiorite intrusion is exposed at
surface in the project area. Unlike the volcanic rocks, the subvolcanic intrusion has no
identifiable volcanic textures or specific orientation and appears to outcrop at surface in an
irregular shape. The monzodiorite is texturally fine to medium grained, porphyritic and similar in
appearance to the ignimbrites. It could easily be misinterpreted as a flow or pyroclastic unit yet is
distinguishable by the uniform distribution of phenocrysts, which includes a higher percentage of
ferromagnesian (predominantly pyroxene) minerals.
Dykes within the study region also have a composition range from intermediate to felsic.
Most of the dykes are very fine-grained diorite with lesser amounts of the more felsic varieties.
The dykes are typically approximately a meter wide but can range up to several meters. One
uniquely large intermediate-felsic dyke in the Bea area is ~160 m wide, infilling an obvious
major dextral fault structure (Figs. 8, 11). There is a consistent orientation for most of the dykes
in the NE-SW direction from an azimuth of ~029° to 065°. The most prominent plutons from the
Mazenod Lake area are described further below:
(a) Sarah Lake Granite
The Sarah Lake granite (SM, Figs. 8, 9, 11) is compositionally a monzogranite within the
study area and acts as the western border of the volcanic belt. The granitic rock is mostly
homogeneous and grades from medium to coarse-grained, west to east. Mineralogy includes
abundant phenocrysts of quartz, feldspars, and relatively minor amounts of hornblende ± biotite
- 43 -

(Gandhi, 2013). The intrusion has a prominent right-lateral offset of ~1200 m along the Marian
River fault in the central area of Mazenod Lake (Figs. 8, 9). Aplitic dykes of similar composition
to the Sarah Lake granite intrude the adjoining rhyodacite.
(b) Marian River Batholith
The eastern extent of the volcanic belt is constrained by the Marian River batholith (MB,
Figs. 8, 9). Composition of the batholith ranges from granite to granodiorite (felsic –
intermediate). It forms the eastern boundary of the entire Faber volcanic belt and is present
throughout most of the GBMZ between the Medial Zone and volcanic belt. Gandhi et al. (2001)
described the batholith as granodiorite characterized by euhedral feldspar crystals set in a
medium to coarse-grained matrix of feldspar, quartz, hornblende, biotite and accessory minerals.
The Marian River batholith was not of significant interest during field mapping; consequently, it
was not examined in detail.

Faber Lake Volcanic Rocks
The Faber Group consists of volcanic and volcaniclastic rocks (Figs. 13, 14) that form an
approximately 85 km long and 10 km wide belt (Gandhi et al., 2001). Most of the lithology is
intermediate in composition but ranges from basaltic andesite to rhyodacite (see Chapter 7 for
chemical classifications). The suites of rocks are calc-alkaline in chemical character and have
been extensively hydrothermally altered (Gandhi, 1994). Metamorphic grade is generally subgreenschist facies and there is little to no penetrative foliation visible in the rocks. Despite
limited internal fabric, the Faber Group rocks are intensely structurally broken. Typical examples
of brittle and ductile deformation are visible in outcrops throughout the region. In this thesis,
volcanic lithology within the project area is subdivided and discussed as five unique volcanic
assemblages.
- 44 -

(a) Volcanic Sediments
Volcanoclastic sediments (VS, Figs. 8, 9, 11) are a coeval suite of rocks derived directly
from the local volcanic rocks (Fig. 14). These rocks consist of detrital and pyroclastic material
reworked into sediments that range from claystone to conglomerate types- although the most
common beds are fine-grained. They contain excellent preserved structures from which to
measure bedding planes and obtain geopetal indicators (way-up structures). Previous mapping by
Gandhi (2013) grouped these rocks with adjoining volcanic assemblages. The sediments have
been separated on maps included with this thesis to emphasize the noncomformity they represent
between the sub-parallel series of volcanic assemblages.
(b) Dianne Lake Assemblage
The Dianne Lake assemblage (DL, Figs. 8 - 10) had been referred to as a series of
rhyolitic rocks and a sub-volcanic intrusive assemblage related to the Lou Lake assemblage
(Gandhi et al., 1996, 2001, 2013). Analysis of geochemical data reveal a compositional range,
with more intermediate rocks on the west and felsic rocks on the east. The geochemical trend is
interpreted to represent evidence of a change in magma composition over time. Unfortunately, a
lack of chronologic indicators prevents conclusive interpretations of how the magma changed
composition over time (i.e. intermediate to felsic or felsic to intermediate composition). The few
bedding measurements taken from layers of ash and preserved fiammé correspond with an
average dip of ~70° to the east.
Each of the different rock layers (ignimbrite sheets) within the Dianne Lake assemblage
has similar mineralogy and textures. The rocks contain 10 – 40% feldspars that range from ~1 –
4 mm in diameter and contain trace to 4% quartz phenocrysts that range from ~1 – 2 mm. The
more felsic ignimbrite sheets contain a small percentage of fine to medium grained biotite
- 45 -

505269E, 7065077N

502275E, 7064686N

505035E, 7056106N

502834E, 7066364N

502227E, 7066364N

501684E, 7066936N

Fig. 13. Outcrop photographs of volcanic assemblage rocks discussed in this thesis: (a) KR289:
Rhyodacite crystal tuff (LL) containing fiammé oriented 289°/71°, (b) HM077: Andesite quartzfeldspar crystal tuff (BL) with fiammé oriented 327°, (c) SR467: Quartz amygdules in a finegrained andesite (SL), (d) KR135: Andesite volcanic breccia (DL) with cooling rings, volcanic
bombs are ~30-40cm, (e) HM088: Finely laminated bedded rhyodacite ash tuff (DL) with a
bedding orientation of 228°/55°, (f) HM367: Welded crystal tuff (ML) with distinct bedding
orientation 189°/60°. Reference system for coordinate data is UTM NAD83 zone 11.

- 46 -

503196E, 7064111N

503126E, 7064138N

. 503213E, 7063391N

503117E, 7063604N

503117E, 7063604N

503037E, 7063435N

Fig. 14. Outcrop photographs of several different facies and textures of volcaniclastic sediments
(VS) that are discussed in this thesis: (a) JS054: Cross bedded arkosic siltstone with beds of cherty
muds. (b) JS056: Interbedded tuffaceous unit of fine-grained ash and mud. (c) JS100: Right
laterally displaced, deformed thin bedded sediment. (d) JS103: Well bedded, strongly magnetic,
matrix supported, monomictic conglomerate. (e) JS103: Same outcrop as previous with
stratigraphic indications highlighted. (f) JS128: Selective alteration and replacement of
sedimentary layers with epidote. Reference system for coordinate data is UTM NAD83 zone 11.

- 47 -

phenocrysts- typically ~1 – 3%. Several facies of the ignimbrite sheets are visible in the outcrops
including ash tuffs, crystal tuffs and volcanic breccias. Macroscopic trachytic textures are also
visible in several outcrops within most of the ignimbrite layers (Gandhi et al., 2001).
(c) Lou Lake Assemblage
The main exposed extent of the Lou Lake volcanic assemblage (LL, Figs. 8, 9, 11) is
south of the study area, near the NICO deposit and in vicinity of Lou Lake (Gandhi et al., 1996,
2001). At the southeastern end of Mazenod Lake, the Lou Lake assemblage is the eastern and
western limit of the local volcanic belt. The chemical composition of these rocks is transitional
between rhyodacite and andesite. Textural variations include forms of ash, lapilli and crystal
tuffs. Locally stretched fiammé and eutaxitic textures are commonly visible in outcrop.
Measurements of the volcaniclastic textures taken from the western portion of the Lou Lake
rocks dip ~75° NE while the eastern rocks dip in the opposite direction at ~75° SW. The rocks
typically contain 5 – 30% phenocrysts of feldspars that are 0.5 – 3 mm in size and 3 – 4% quartz
crystals that are microscopic to 2 mm in size. Within the explored outcrops, very fine-grained
biotite crystals are present in minor to trace amounts. At the northern border of the assemblage it
is intruded by a monzogranite pluton and right laterally offset by the Marian River fault.
Nod Hill rocks are grouped with the Lou Lake assemblage in the geologic maps (Figs. 8,
9), consistent with their spatial association and a pre-existing mapping interpretation of Gandhi
et al. (2001, 2013). Despite the similar grouping demonstrated in the geologic maps for this
report, the Nod Hill rocks have a unique chemical composition. Their distinctiveness is defined
by a deficiency of REEs as compared to other rocks in the region (see Chapter 7, Fig. 28,).
Most of Nod Hill is intensely hydrothermally altered, making specific and accurate
descriptions of the precursor rock difficult. The following lithology descriptions are derived from
- 48 -

the southern portion of Nod Hill where the least altered rocks are visible. The representative
samples from Nod Hill are rhyodacite crystal tuffs that contain 7 – 12% phenocrysts of 1 – 2 mm
feldspars as well as 2 - 3% quartz phenocrysts that are 2 - 3 mm in size. The phenocrysts are
hosted within an aphanitic matrix that is greyish on the fresh surface. Weathered surfaces of the
rock are generally pinkish orange to a brick red color. The intensity of alteration is strongest at
the northern portion of the hill in close spatial association with faults that cut across Nod Hill.
This area is an excellent example of the spatial association between hydrothermal alteration and
faults, where intensity of alteration has a direct correlation to proximity and intensity of faulting.
The strength of the hydrothermal alteration is exemplified by large-scale actinolite breccias that
transition to massive magnetite and magnetite-cemented breccias exposed on the face of a faultgenerated scarp. Crackle breccias are a common structural observation in the higher-intensity
alteration zones. The breccias are typically cemented with either massive magnetite and/or a
coarse-grained to megacrystic actinolite, often accompanied by quartz. The brecciated and
intensely altered rock lies along a dextral shear zone, a continuation of the Kemaz fault
(Ketcheson Lake-Mazenod Lake fault), that trends NNE-SSW and terminates at the Sue-Dianne
deposit (Gandhi et al., 2001). This transverse right lateral fault bisects the center of Nod Hill
with an offset of a few 10s of meters. The unique rocks from Nod Hill appear to be entirely
constrained within the Lou Lake volcanic assemblage, although they may extend further to the
south and/or southwest below overburden.
Unconformably separating the western portion of the Lou Lake assemblage from the
younger Squirrel Lake assemblage is an almost 2 km wide range of volcanic derived sedimentary
rocks. The eastern portion of the Lou Lake assemblage has a direct contact to both the Squirrel

- 49 -

Lake assemblage and the Dianne Lake assemblage. Geopetal markers show that the Squirrel
Lake and Dianne Lake assemblages are stratigraphically younger than the Lou Lake assemblage.
(d) Squirrel Lake Assemblage
The Squirrel Lake assemblage (SL, Figs. 8-11) refers to a newly identified dacite
ignimbrite flow. Typical exposed outcrops of this volcaniclastic assemblage are massive crystal
tuff facies, with textures that are sometimes seriate and locally trachytic. Exposed lapilli and
breccia volcaniclastic facies exist in the southwestern portion of the Bea area (Fig. 11). There is
also at least one example of a layer of the dacite containing quartz amygdules. The assemblage is
consistently rich in 2 – 5 mm diameter plagioclase phenocrysts that range from 15 - 30% modal
abundance. Often the rock contains biotite up to 5 modal % and 1 - 2 mm in diameter.
Volcanic breccia found in the southwestern portion of the Squirrel Lake assemblage is
monomictic, containing subangular clasts from 1 - 40 cm in size. It is mostly matrix supported
but locally clast supported. Dark grey-black clasts make up ~20% of the breccia and are very
strongly magnetic (~70% magnetite estimated volume), unlike the red-grey matrix material.
Feldspar phenocrysts within the clasts are oriented along the same axial direction as the clasts.
(e) Bea Lake Assemblage
The Bea Lake volcanic assemblage (BL, Figs. 8-11) occupies the center of the volcanic
belt. It is comprised of a relatively mineralogically uniform andesite ignimbrite. The extent of the
assemblage ranges from almost 3 km southeast of Sarah Lake to approximately 1 km north of
Lou Lake (Gandhi et al., 1996, 2001). Volcaniclastic rock facies vary from ash tuff, to lapilli
tuff, to pyroclastic breccia. The Bea Lake assemblage had previously been identified as
rhyodacite by Gandhi et al. (2014), but has been reclassified in this work as andesite to reflect
the classification schemes of Pearce (1996) (Chapter 7, Figure 28). Bedding measurements show
- 50 -

a consistent dip of ~70° NE on the east and south end of Mazenod Lake, whereas it dips ~70° in
a more northerly direction west of the lake.
The typical andesite within the Bea Lake assemblage contains up to 30% plagioclase
euhedral phenocrysts that range from 1 – 6 mm in size. The andesite also contains varying
quantities of quartz phenocrysts from 5 - 30% that are 1 – 6 mm in diameter. Phenocrysts are
hosted within a light to dark grey aphanitic matrix.
On Dan Island, the contact between the andesite and rhyodacite is difficult to define as
the entire island is intensely and pervasively hydrothermally altered. Many of the outcrops on the
island are intensely potassic altered. The most intense of the potassic altered rocks are found in
rocks at the highest elevation, near the center of the island and adjacent to part of the Kemaz
fault. There are also several other examples on the island of other hydrothermal alteration
products, including varying quantities of tourmaline, magnetite, hematite and/or epidote. Less
abundant, although still present throughout the island in differing concentrations are sulphides
such as pyrite, chalcopyrite and pyrrhotite.
(f) Mazenod Lake Assemblage
The exact stratigraphic position of the Mazenod Lake assemblage (ML, Figs. 8-9) is not
clear from the 2013 field mapping; however, previous work of Gandhi et al. (2001) and Camier
(2002) suggest the volcanic assemblage is the oldest product of volcanic activity exposed at
surface. These volcanic rocks extend from the northern shore of Mazenod Lake to almost 4 km
north, near Dianne Lake. The surface showing of the Sue-Dianne deposit is constrained within
the Mazenod Lake volcanic assemblage (Goad et al., 2000; Gandhi et al., 2001; Camier, 2002;
Mumin et al., 2010; Gandhi, 2013).

- 51 -

The explored portion of the Mazenod Lake assemblage is dominantly comprised of
rhyodacite crystal tuff. On average, these rocks contain ~10 – 15% feldspar phenocrysts that are
~1 – 3 mm in diameter within a light grey aphanitic matrix. In local areas, pitting was identified
indicating weathering of sulphides. The fresh surface of the rock is generally a light grey color.
No significant structures were observed in the outcrops during the 2013 mapping project;
however, Gandhi (2013) reported shallow bedding in the rhyodacites oriented at 25 – 30° NE.

Hydrothermal Alteration
Rocks in the Mazenod Lake region have been pervasively affected by hydrothermal
alteration (Fig. 15). Field observations include examples of magnetite ± actinolite (MA),
potassic, sodic, hematite, magnetite, phyllic, tourmaline, propylitic and silica alteration types.
Silication is also visible in core samples that originate from a drill program completed by Phelps
Dodge in 2005. These alteration types are all commonly associated with IOCG systems, which
are also present throughout the GBMZ (Mumin et al., 2007; Corriveau et al., 2010; Mumin et al.,
2010; Montreuil et al., 2013).
(a) Magnetite ± actinolite (MA) alteration
Magnetite ± actinolite (MA) alteration occurs in several different mineralogical
combinations and textural forms in local areas throughout the Mazenod Lake region (Figs. 15a,
15b, 15c). Most often this alteration is visible as veinlets of very fine-grained dark green
actinolite often accompanied with trace amounts of magnetite. Alteration visibly strengthens in
intensity from a minor presence of veinlets to areas with more widespread veining and examples
of megacrystic actinolite resembling pegmatite. This occurs significantly at Nod Hill where

- 52 -

502540E, 7065013N

502286E, 7062008N

502366E, 7061927N

502638E, 7065028N

502219E, 7063706N

500991E, 706300N

Fig. 15. Outcrop photographs of hydrothermal alteration types discussed in this thesis: (a) HM053:
Crystal tuff containing magnetite veins throughout the rock, up to >5cm in diameter, (b) SR434:
Megacrysts of actinolite form in zone of MA alteration; the host rock is largely brecciated and
cemented with predominantly massive actinolite, (c) SR372: Crackle breccia that is cemented by
actinolite-quartz-magnetite alteration minerals, (d) HM389: Fractured volcanic breccia with a strong
potassic alteration overprint that affects more permeable volcanic bombs greater than host rock, (e)
SR198: Brick red hue from a micro-dusting of hematite within a dacite ignimbrite. Also contains
veins of specular hematite, (f) SR052: Pervasive potassic alteration and chemical weathering that
affects both the monzogranite and an intruding dyke.

- 53 -

501133E, 7062685N

502443E, 7064769N

502585E, 7065237N

504366E, 7063445N

501633E, 7062367N

501727E, 7065581N

Fig. 15 (cont.). (g) SR090: Coarse grained monzogranite inundated by a stockwork of quartz veins
and silica flooding, (h) HM066: Green staining along fractures representing epidote alterationwithin an intersection zone between two conjugate fracture sets, (i) HM058: Tourmaline cemented
crackle breccia. Host crystal tuff was potassic altered prior to being brecciated and cemented, (j)
JS209: Autochthonous sedimentary rock brecciated and cemented with quartz, (k) SR014:
Specular hematite associated with fractures in a crystal tuff, also contains trace amounts of
magnetite, (l) HM164: Jasper stockwork within a crystal tuff, also associated with local quartzepidote veining. Reference system for coordinate data is UTM NAD83 zone 11.

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abundant stocks, veins and masses of actinolite ± magnetite ± quartz replace and cross-cut the
rhyodacite host rock. The most extreme cases of MA alteration are large crackle breccias, where
megacrysts of actinolite ± magnetite ± quartz cement fractured host rock. While magnetite and
actinolite are often found together they also exist independent of each other.
The most commonly associated accessory mineral observed with MA alteration is
epidote, which typically rims actinolite or directly cross-cuts of MA altered rocks. Outcrops also
often contain trace amounts of pyrite ± chalcopyrite ± pyrrhotite that coexist with MA alteration.
The mineralization generally occurs as clots of subhedral sulphides, occurring within or along
the outer edge of veins of actinolite ± magnetite.
(b) Potassic alteration
Potassic alteration (K-feldspar ± magnetite ± biotite ± hematite ± sericite) is ubiquitous
throughout the Mazenod Lake region, although it varies in intensity (Figs. 15d, 15e, 15f, 15g,
15h, 15i). Typically, the potassic alteration is recognizable as a pinkish color, orangey-brown, or
bright orange hue. The altered rocks visibly change shades of color according to intensity and
style of potassic alteration. Locally, potassic alteration occurs as K-feldspar veins and/or
veinlets. All other types of alteration identified in the field exist in conjunction with the widespread potassic alteration or occur independently. Paragenetic evidence from cross-cutting and
overprinting features that replace the pervasive K-feldspar alteration indicate there was an early
regional phase of widespread potassic alteration (Fig. 15e).
The highest recorded scintillometer readings (K: 8.6 wt. %) and highest reported
lithogeochemical values of K2O content (12.8 wt.%) were identified at Dan Island and correlate
with observations of the most intensely potassic altered rocks. At Dan Island, the alteration
reaches greatest intensity at the highest elevation near the Kemaz fault, which crosses the center
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of the island. Spatial association between intensity of potassic alteration and this significant fault
suggests that it was major hydrothermal fluid conduit. Camier (2002) made a similar
interpretation of the Kemaz fault another 4 km NE of Dan Island at the Sue-Dianne deposit.
(c) Tourmaline alteration
Tourmaline alteration typically occurs as black sooty veins and veinlets that range from
mm to cm scale, with few local examples of massive replacements. The alteration is found
locally throughout the study region in all types of rocks, but is dominant in the Bea area and NW
end of Dan Island. Potassic, epidote and/or hematite alterations are often associated with or
proximal to tourmaline altered rocks. Pyrite and lesser chalcopyrite sulphides are also commonly
associated with tourmaline alteration in the Bea area. The mineralization locally occurs as clots
of subhedral sulphides or disseminated within massive tourmaline in trace quantities.
One of the most intense tourmaline altered zones is along the northwest side of Dan
Island, where the tourmaline occurs as cement for a crackle breccia (± hematite) overprinting
potassic altered rocks (Fig. 15i). In the Bea area, the tourmaline alteration is more wide-spread,
with local bodies of a massive replacement of host ignimbrites that can be greater than 5 m2.
(d) Hematite alteration
Hematite alteration occurs as a local massive replacement, fracture/vein fill or as
disseminated specularite throughout the region, in all rock types (Figs. 15a, 15k, 15l). Veins and
disseminated instances of hematite are typically a black, dark brown or reddish-brown color,
locally accompanied by a reddish oxidized stain surrounding the minerals. Hematite alteration is
also manifest in outcrops by a brick red color that occurs in the vicinity of fractures and
encompassing wide zones at Dan Island, Nod Hill and in other local areas. The red color is

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thought to be a result of submicron inclusions of hematite within K-feldspar and possibly other
minerals.
Local hematite alteration exists independently of other alteration minerals, occurs along
with magnetite veins, within tourmaline crackle breccia, and in conjunction with silicified rocks
across the study region. Jasper (quartz with embedded hematite) also occurs, dispersed
throughout the field mapped area in comparatively rare instances.
(e) Phyllic alteration
Phyllic (sericite, quartz ± pyrite) alteration occurs locally throughout the Mazenod Lake
region. More often, quartz and sericite occur together or independently and typically absent of
any sulphides. Thin section studies of on both igneous and volcanic rocks show that microscopic
sericite ± quartz is widespread as pseudomorphic replacement of groundmass and feldspars
phenocrysts. This microscopic sericite is not visually identifiable in hand sample. For example,
hand samples taken from the intrusion immediately west of Net Ridge contain apparently
euhedral feldspar phenocrysts; however, thin section analysis shows the feldspars to be strongly
sericitized. Partial sericite pseudomorphs after feldspar indicate that the presence of sericite is a
result of destruction of feldspars.
(f) Epidote alteration
Epidote alteration (epidote ± quartz ± carbonate ± chlorite ± sericite) is one of the more
common alteration types found in the Mazenod Lake region (Fig. 15h). Epidote alteration
usually occurs as mm to cm-scale ‘pistachio’ green veins, which exists locally throughout the
study region. In relatively rare cases, massive epidote replacements and hydrothermal breccias
exist, which are typically only a few square meters. For example, approximately 350 m SW of
Dan Island is another island that contains a crackle breccia cemented by massive epidote.
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The microscopic studies have identified epidote veins that cross-cut and replace preexisting actinolite veins and recrystallized K-feldspar, suggesting that epidote alteration is a
younger alteration than MA and potassic alteration.
(g) Silicification
The most predominant silicification occurs along NE-SW oriented transcurrent faults,
which are cemented by silica to form giant quartz veins. Along the faults and in proximity to
them are milky white quartz stockworks, hydrothermal breccias, veins, and massive
pseudomorphic replacements (silica flooding) (Figs. 15g, 15j). Any other silicification within the
region is typically associated with subsidiary fractures/faults adjoining the transcurrent faults.
Hematite (as specularite) is an associated hydrothermal alteration mineral, which occurs
disseminated along the giant quartz veins. Sulphides are typically distinctly absent from zones of
silicification; however, a uraninite showing on the western side of Net Ridge along the Marian
River transcurrent fault was drilled by Noranda in the 1970’s. There is also a small quartz
flooded outcrop a few square meters in size located at UTM NAD83 zone 11 499931E,
7064456N (±5 m) that contains 1-2% euhedral pyrite grains.

Mineralization
Several varieties of mineralization have been observed across the extent of the Mazenod
Lake region, although not in significant quantities. Over the course of the regions exploration
history Cu, Mo and Co as well as U and LREE-bearing minerals have been discovered.
Chalcopyrite (CuFeS2) is the most common metal-bearing mineral observed in the region.
Concentrations of the chalcopyrite and other metal-bearing minerals is typically minor. The
highest recorded values of chalcopyrite occur in a few isolated portions of outcrops, estimated up
to 5% by volume. The rest of the metal-bearing minerals, such as cobaltite (CoAsS) and
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uraninite (UO2) are present in minor to trace amounts, also within isolated areas. The copper and
cobalt sulphides are characteristically accompanied by their weathered mineral products
including malachite (Cu2CO3(OH)2) and erythrite (Co3(AsO4)2·8H2O), respectively. For field
identification, distinctive patches of gossans that are rusty in appearance are a good indication of
sulphides (typically trace amounts of pyrite, FeS2) within a few cm of the surface.
Cobaltite and erythrite was discovered during the course of 2013 field work on an island
<1 km northeast of Dan Island (Fig. 9, 10). The Co-bearing minerals are accompanied by
chalcopyrite and pyrite, all of which are in trace quantities and hosted in the Bea Lake
assemblage andesite crystal tuff. Cobalt minerals are restricted to the islands east of Dan Island;
however, the pyrite and chalcopyrite have also been found on several of the surrounding islands.
Equant pitting is abundant in these areas, particularly on the eastern side of Dan Island,
indicating weathering of pyrite and potentially other sulphides.
A minor amount of uraninite is visible at surface at the SW portion of Net Ridge (Fig. 9).
The uranium mineralization is located at the contact between the Lou Lake volcanic assemblage
and the Sarah Lake monzogranite, along the Marian River fault. Exploration trenches expose the
showing of mm-scale veins of uraninite. Local alteration surrounding the showing includes the
presence of drusy quartz and specular hematite.
The LREE-bearing mineral allanite ((Ce,Ca,Y,La)2(Al,Fe+3)3(SiO4)3(OH)) is
recognizable in core samples originating from the Phelps Dodge 2002 drill program (Hamilton,
2013). Extent and quantity of allanite within the drill core is currently unknown.
Several magnetite-garnet –pyroxene skarn sections were identified in the core as well,
which contain notable quantities of pyrite, chalcopyrite and pyrrhotite. Core logging performed
by Phelps Dodge geologists had previously incorrectly identified the skarns as magnetite-

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amphibole-epidote altered rocks (Kulla, 2004). A forest fire resulted in damage to the core
samples and boxes that prevents correlation of the core samples to depth of drilling and drill
collar location.
Molybdenite (MoS2) was observed by Gandhi (2013) at UTM coordinates 500010E,
7064478N (±5 m), on an island west of Dan Island. The molybdenite was not encountered during
2013 field work, and the extent of the mineralization is not known.

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Chapter VI: Structural Analysis
Crustal structures play an important role in the formation and location of IOCG-type
mineralization and hydrothermal alteration (Williams et al., 2000; Williams et al., 2005;
Richards and Mumin, 2013b; Mumin et al., 2014). This chapter presents the analysis of the
Mazenod Lake region structural framework with an examination of lineaments derived from
remotely sensed imagery. These linear features generally represent surface expressions of
geologic features, alteration effects and/or structural disruptions within the subsurface. As a
consequence, local supracrustal deformation can be partially revealed by maps and diagrams that
illustrate the distribution of lineaments. With a basic understanding of structure in the lithosphere
and geology of the region interpretations can be made with respect to geotectonic setting and
evolution. Knowledge of the structural framework also provides evidence of tectonic conditions
at the time of magmatism, hydrothermal alteration, and ore deposition.

Lineament Definition
Lineaments have long been acknowledged and used for their representation of structure
in the lithosphere (Richards, 2000). Definitions of lineaments have arisen from a number of
investigations (e.g. Hobbs, 1904; O’Leary et al., 1976; Gabrielsen et al., 2002; Galkin, 2010;
Soto-Pinto, 2013); however, a slightly modified definition from Galkin (2010) represents the
most useful characterization of lineaments for this study. In this thesis, lineaments are interpreted
and derived from satellite images, airborne magnetic survey data and digital elevation data as
linear and arcuate visually contrasting features.

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Methodology
Interpretations of possible structural features within bedrock are based on a visual
inspection of lineaments from a satellite image, aeromagnetic data and digital elevation model.
Lineaments unrelated to geologic structure (such as anthropogenic features) are not included in
structural interpretations. The subjective determination and classification of lineaments is
corroborated by structural data acquired during the 2013 field season and correlation between the
remotely sensed images. This is a necessary step for validating lineaments reflecting real
anomalous physical properties on the earth, such as individual rock bodies (e.g. dykes, sills,
layers or intrusions) or fault ruptures. Human bias and error precludes every structure being
drawn accurately in this subjective interpretation; however, it is an effective method of deriving
an understanding of the local structural framework.
An overview of the methods used in this study to derive and analyze lineaments is
described in more detail below:
(a) Lineament and lineament intersection delineation
The process of identifying and extracting lineaments is a manual process. Linear and
curvilinear features are drawn directly on geophysical or satellite images with the use of both
CorelDraw and ArcMap software. To prevent any systematic errors, no automated techniques for
extracting lineaments are applied in this study. Lineaments are categorized on the basis of
calculated vertical gradient on the aeromagnetic map or extent of topographic features from the
satellite image. Selection of lineaments is based on their importance to the local tectonic
framework, i.e. anthropogenic features are not included as a lineament. The lineament
intersections are extracted using the Arcmap intersect tool, which creates a map of georeferenced
points where lines intersect.
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(b) Analysis of lineament orientations
To analyze and portray preferred orientations and directional data of lineaments a circular
histogram (rose diagram) is depicted along with each lineament map. The radial distance on the
rose diagrams indicates relative frequency of a lineament at a specific azimuth. Orientation data
of the lineaments (called polylines in ArcMap) is extracted by use of a custom-made ArcMap
function. The function reports in spreadsheet format (.csv) the angle of each polyline relative to
north, from the beginning of a polyline and every 5 m to the end of the same polyline. The
orientation data includes all orientations within curved lines as well as straight lines, without
adding any significance to any one type of line preferentially. The spreadsheet data is then
imported into the freeware program GeoRose that generates rose diagrams for each category of
lineament (Georose v. 0.51, 2014).
(c) Analysis of the population density
Lineament intersections are derived from the lineaments using the intersect tool in ArcMap
software. ArcMap uses a kernel function based on the quadratic kernel function developed by
Silverman (1986) to calculate density fields. The line (lineaments or polylines) and point kernel
density functions in ArcMap conceptually fits a smooth curved surface around each lineament or
point. Greatest density is in areas containing the most length of lineaments or points per square
km. The search radius parameter is set to 1 km, which produces a more generalized density
raster. Selected output cell size parameter is the aerial extent of the environment analyzed, which
is set to the area within the satellite image. Individual lines and points are weighted equally.

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Fig. 16. Geo-eye 1 satellite image of the Mazenod Lake region.

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Satellite Image
BFR purchased the GeoEye-1 satellite image in 2012 and provided it for use in this
investigation (Fig. 16). Spatial resolution of the satellite image is 0.5 m. Details visible on the
satellite image are to the extent that individual trees and, more importantly, geologic structures
can be identified with the naked eye with little difficulty. Bedrock exposure in the Mazenod Lake
area is excellent, although still less than 25% overall coverage within the extent of the satellite
image. The exposed bedrock tends to be concentrated in the northern portion of the satellite
image and southeastern corner. Lakes and rivers are also shown to cover approximately 25% of
the study area. The rest of the satellite image shows that the ground is mostly covered with forest

Fig. 17. Close-up image of Net Ridge, Mazenod Lake region, NWT.

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and swamp. The degree of satellite image detail is better illustrated in the close-up image of Net
Ridge shown in Figure 17.

Aeromagnetic Data
Aeromagnetic surveys are important for geologists because of the general correlation of
magnetic susceptibility data to subsurface geology, structure and hydrothermal alteration. Unlike
the satellite image, this magnetic data has a uniform coverage of the area surveyed and is not
dependent on the presence of outcrop for providing useful information.
Goldak Airborne Surveys flew a high-resolution airborne magnetic survey in the fall of
2012. The survey was flown at 60 m height with traverse line spacing of 50 m and control line
spacing 500 m. Direction of the traverse was 90°/270° with a control direction at 0°/180°. The
magnetic system on the plane utilized two vertically separated tail mounted and two wing tip
mounted cesium vapour magnetometers arranged in a three-axis gradiometer configuration.
Goldak Airborne Surveys also performed final processing, leveling, gridding and production of
illustrated aeromagnetic data. Processing of the magnetic data included generation of a measured
vertical gradient (MVG) map (Fig. 18), which is better at displaying near surface magnetic
sources than total magnetic field measurements. The magnetic field gradient data has a greater
variance than total field magnetism; therefore, it shows a higher spatial resolution and is useful
for delineating linear surface features. Although there have been high-resolution aeromagnetic
surveys completed within the Mazenod Lake region prior to this investigation, spatial resolution
is significantly more detailed in this new data (see Hetu R.J. et al., 1994 open file 2806 for
regional aeromagnetic data). BFR provided the aeromagnetic data for use in this study.

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Fig. 18. Magnetic vertical gradient (MVG) data layered over Geoeye-1 satellite image.

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Digital Elevation Model (DEM)
Digital elevation data was also provided for this study by BFR. Areas with differential
relief are significantly more distinct on the DEM than the satellite image (e.g. Paleozoic strata).
The contrasting elevation data is used in this study to link topographic relief to physical and
magnetic data lineations. A visual representation of the differential relief also allows for the
delineation of lineaments that would otherwise be invisible and can improve the accuracy of
orientations of lineaments derived from the satellite imagery. ArcMap software was used to
construct the digital elevation model (Fig. 20).
Elevation in the Mazenod Lake area ranges from 194.7 m to 348.9 m above sea level.
Highest elevation features include quartz cemented fault structures, areas covered by Paleozoic
strata and a few isolated circular features with pervasive hydrothermal alteration, such as Dan
Island. Lowest elevation areas include Mazenod Lake, rivers and the southwestern portion of the
DEM.

Field Mapping
Without a reliable geologic understanding of a region, it would be impossible to
accurately correlate the satellite image and geophysical data to real supracrustal structures. A
1:2000-scale field mapping program resulted in the construction of several detailed geologic
maps (Chapter 5, Figs. 8 to 11). These maps, along with field notes and field experience form the
basis for correlation of lineaments and geologic structures. Field structural observations are
summarized in Figs. 19a, b.

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Fig. 20. Overlay of digital elevation data and lake/river outlines on Geoeye-1 satellite image.

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(b)
Amount of
measurements

(a)

Angle of dip

Fig. 19. (a) Half rose diagram showing the frequency of strike direction measurements taken in the
field for faults, fractures and vein structures. (b) Histogram diagram showing the frequency of dip
angle measurements taken in the field for fault, fracture and vein structures. N=303.

Satellite Image Lineaments
Lineaments extracted from the high-resolution satellite image occur as linear and
curvilinear features that represent topographic features, such as: ridges, valleys, depressions,
lake/island morphology, or shallows (Fig. 21). The linear features are easily recognizable by
visually distinct expressions of topography (e.g. rivers, shallows, depressions and prominent
elevation contrasts). Similar studies have shown that lineaments extracted from satellite images
correlate well with geological features at all scales of observation (Mumin et al., 2014). The
lineaments are commonly considered to be a result of different rates of erosion and weathering
over long periods of time (predominantly from glaciation, but also from interglacial weathering)
that highlights contrasting competency across the lithology. The excellent outcrop exposure in
the Mazenod Lake area is particularly effective at revealing structure. Therefore, lineaments on
remotely sensed images will often represent faults, shear zones, brecciated structures,
differentially hydrothermally altered rock, and/or lithological contacts. The interpretation of
lineaments as geologic features is further verified with corroborating evidence from field
mapping.

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Fig. 21. Mazenod Lake area satellite image lineament interpretation. Anthropogenic features (cutlines, roads) have been removed from this interpretation.

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Any lack of discernible lineaments tends to be reflective of areas with lesser amount of
rock exposure. Proterozoic lineaments of structural features are obscured by sedimentary cover
and overburden. In a few areas, geomorphic features accentuate certain structures, such as faults
that control the direction of rivers. Although there are many distinct long linear features that
stand out on the satellite image, there is a large variation in length, width, depth and orientation
across the scope of all the lineaments. To show the different characteristics of lineaments they
are classified based on a subjective determination of length and prominence. The first order
lineaments are the longest trending and most prominent linear features, while second orders are
mid-range lineaments and third orders are the shortest linear features identified on the satellite
image. Rose diagrams show the unique trends associated with each classification of lineament.

Fig. 22. Close-up image with lineaments drawn on Net Ridge, Mazenod Lake region, NWT.

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First order lineaments have three main directional tendencies that are oriented at ~050°, ~020°
and to a lesser extent ~330°. These orientations correspond with the major regional tectonic
fabric that have a notable manifestation in the topography. Second order lineaments predominate
in the general E-W direction. Third order lineaments have a large diversity of orientations;
however, they do closely match the first and second order lineament orientations in relative
abundance. The degree of satellite image detail is better illustrated in the close-up image of Net
Ridge shown in Figure 22.

Magnetic Lineaments
Magnetic lineaments in this study are defined by the magnetic vertical gradient (MVG) high and low intensity anomalies. The MVG lineaments have many similarities to lineaments
recognized on the satellite image and to the distribution of geologic units recognized in the field
(Fig. 23). For example, NW-trending MVG high intensity lineaments correspond with unique
volcanic rock types mapped in the field. Most of these features have an almost tabular shape on
the aeromagnetic data, with mostly equivalent orientations. There is a definite pattern to the
MVG high lineaments that follows the NW orientation of the volcanic belt with a slight obliquecurve shape. In the northern portion of the aeromagnetic data this general trend is reversed,
where the magnetic anomalies and mapped geology follow NE and NW orientations.
The high resolution MVG aeromagnetic data correlates well with belt-scale structures.
Four of the most prominent, MVG low intensity, NE oriented lineaments occur along faults
(Dianne Lake fault, Marian River fault, Squirrel Lake fault and Bea fault). These lineaments
have a similar orientation with an average azimuth of ~050°. Low MVG intensity lineaments
also trend in two other dominant orientations at ~330° and 020° which correspond with similar
orientations of the Kemaz and Cross Lakes faults. In general, directional tendencies of the main
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Fig. 23. Magnetic vertical gradient (MVG) data lineament interpretation layered over Geoeye-1
satellite image.

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MVG low intensity lineaments correspond well with Tier 1 lineaments derived from the satellite
image and regionally occurring faults mapped in the field.
There are three distinct zones where lineaments that have similar orientations to each
other dominate, including the area north of the Marian River fault, the area between the Marian
River fault and the Squirrel Lake fault, and the area south of the Squirrel Lake fault. South of the
Marian River fault within the volcanic terrain the majority of lineaments orient ~330°. The
remaining lineaments mostly trend towards ~016° and 065°. Above the Marian River fault there
is a higher variance to the directional trend of high and low MVG lineaments. The main
orientations of note trend at ~95°, ~050°, ~325° and ~016°.
Felsic intrusions are typically MVG low magnetic intensity features that have mostly no
linear characteristics. The few lineaments that occur within areas underlain by felsic intrusions
typically orient at ~050° and 020°, in conjunction with known faults. Dykes are normally too
small-scale to be identified on the aeromagnetic data.
Impact of hydrothermal alteration on the magnetic signature of the Mazenod Lake region
is significant on both a volcanic belt-scale and a local scale. The dominant NE-SW oriented
MVG low intensity lineaments are underlain by giant hydrothermal quartz veins, stockworks and
silicification. These quartz-rich structures form prominent aeromagnetic lows because of the low
magnetic susceptibility of quartz in contrast to the surrounding rocks. The low intensity
magnetism of the quartz veins is also obvious on regional magnetic survey data (Hetu, R.J. et al.,
1994). There are also examples on the aeromagnetic data of high magnetic intensity lineaments
that correlate with previously noted field observations of hydrothermal magnetite (Camier,
2002). This observation includes the semi-circular magnetic high Sue-Dianne deposit. Previous
work has shown the high magnetic intensity signature of the deposit is a result of abundant

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hydrothermal magnetite at depth within the deposit. There are several other prominent magnetic
anomalies in the aeromagnetic data that are similar in shape and magnetic intensity to the SueDianne deposit, including Dan Island, Nod Hill and a few isolated smaller-scale magnetic
anomalies. Most of these MVG highs are semi-circular features that occur in areas with high
relief.

Lineament Density Models
The purpose of a lineament density model is to illustrate lineament and lineament
intersection population density. Zones that have a great density of lineaments and intersections
are often associated with areas of greatest strain and permeability for fluid flow (Galkin, 2010).
Identifying these areas is important for determining potential locations that have the space
necessary for fluid migration and ore deposition.
(a) Satellite image lineament population density
The population density map of lineaments derived from the satellite image (Fig. 24)
distinctly shows the correlation between the abundance of lineaments and outcrops. They are
most abundant in the northern and southeastern portions of the study area, and least abundant in
areas overlain with Paleozoic sediments and part of Mazenod Lake. Some of Mazenod Lake
contains a dense zone of lineaments, where lines were drawn along outcrops on islands, along
shorelines and similarly oriented (shaped) islands. This data is highly skewed towards areas with
high outcrop exposure; therefore, any interpretation of the lineament density population would
be significantly biased.
(b) MVG data lineament density
The most abundant MVG lineaments follow the trend of the volcanic belt (Fig. 25). Areas
with less presence of lineaments correspond to locations known to contain Proterozoic granitoid
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Fig. 24. Kernel density model showing the population density of lineaments per square kilometer,
derived from the satellite image.

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Fig. 25. Kernel density model showing the population density of lineaments per square kilometer,
derived from the MVG data.

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batholiths. Whether this pattern continues underneath areas overlain with Paleozoic cover
remains unknown, but is suspected. An important observation is that there is no significant
correlation between the abundance of lineaments and the presence of Paleozoic strata. Instead,
the density of MVG lineaments highlights the difference between younger plutonic (lower
density of lineaments) and older volcanic rocks (higher density of lineaments).
(c) MVG data lineament intersections density
Stretched contours showing the concentration of MVG lineament intersections per square
kilometer show similar anomalies to the MVG lineament density map (Fig. 26). Along the
Marian River and Cross Lakes fault in the northern part of the study region are relatively large
high-density lineament intersections anomalies. This zone also exists along the contact between
the Marian River batholith and Faber Group volcanic rocks. Similarly, in the Bea area a smaller
dense zone of lineament intersections occurs at the eastern contact of the Marian River batholith
and Faber Group volcanic rocks. The Bea fault also intersects the high-density anomaly. In
general, the medium density anomalies coexist along recognized regionally cross-cutting faults.
Low densities of lineament intersections typically occur outside of the volcanic belt, within the
granitoid batholiths. The western part of Mazenod Lake has no presence of lineament
intersections.
Similar to the other lineament population density maps, the data is skewed towards areas
with higher outcrop exposure. Any interpretations derived from this data would be highly biased
towards these areas.

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Fig. 26. Kernel density model showing the population density of lineament intersections per square
kilometer, derived from the MVG lineament map.

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Chapter VII: Geochemical Data Analysis
This chapter is dedicated to an analysis of lithogeochemical data. The geochemical data
are from 906 grab samples collected in the Mazenod Lake area, covering an area ~36 km2. The
samples include 15 boulders, 3 quartz veins, 52 sedimentary rocks, 99 intrusive rocks, 724
volcanic rocks and 13 core samples (Fig. 27). All rocks collected are hydrothermally altered,
with 13 of the samples selected as representative samples of lithology.
Saskatchewan Research Council (SRC) Geoanalytical Laboratories performed multielement analysis of the samples. The geochemical analysis includes whole-rock and trace
element analysis by lithium meta-borate fusion, inductively coupled plasma mass spectrometry
(ICP-MS) and fire assay for Au. Fifty-nine elements were reported by the SRC, generating
53,336 geochemical data points, with 2D spatial control. Analytical parameters for the
geochemical testing are available from SRC Geoanalytical Laboratories. Major elements are
reported as weight percent oxide (wt.%), trace elements in parts per million (ppm) or parts per
billion (ppb) and total iron is reported as Fe2O3. The geochemical data is included in a digital file
accompanying this thesis (Mazenod Geochem Data.xls).
Whole-rock geochemical results of major and trace elements are presented qualitatively
and quantitatively within this chapter. Geochemical discrimination diagrams are used to
chemically classify rocks. This information is used to develop a two- dimensional chemical
lithology map of the region that shows the distribution of rock types as discriminated by
geochemistry. The mass balance method of lithogeochemical data analysis is used to calculate
and graphically illustrate element gains and losses for several geochemical discriminations of

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Fig. 27. Locations where geochemical samples were collected in the field at Mazenod Lake, NWT. Digital
elevation data courtesy of the Ministry of Natural Resources.

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hydrothermally altered and mineralized rocks. The results of mass balance calculations are used
as a basis for the generation of diagnostic residual alteration indices (RAIs), which are
interpolated and illustrated to show the spatial distribution of hydrothermal alteration intensity
for several of the alteration types identified in the region.

Filtering Data and Handling Detection Limits
With any large geochemical dataset, it is important to organize, prioritize and prepare the
data for statistical analysis. In this study, concern is for the igneous and sedimentary rocks
originating from the Mazenod Lake region. The compositional data had to be filtered so that only
those rocks that are involved in this analysis are present in the data. The remaining boulders, vein
material, and core samples are not useful for characterizing lithology and/or hydrothermal
alteration; consequently, they are not included in the following analyses.
In geochemical analyses, elements (such as Au) often have values below the detection
limit. Despite the lack of accurate detection, these elements are still of interest for this study. To
facilitate modelling, any element value below the detection limit is converted to half of its
detection limit (Table 3). Any duplicate data within the lithogeochemical data is not applied in
the following analyses. This anomalous data constitutes only a very minor portion of the
geochemical data.
TABLE 3. Adjustments made to values in the geochemical data under the detection limit.
Detection limit
Converted value
<2
1
<1
0.5
<0.1
0.05
<0.01
0.005
<0.001
0.0005

- 83 -

Least Altered Representative Samples
In order to geochemically discriminate rock types and reveal mass changes in
hydrothermally altered rocks, it is necessary to have a reference composition per rock type. This
reference value is typically acquired from a parent (precursor) rock that represents the original
composition (i.e. the rock remains unaltered). Field work and petrographic studies (Appendices 1
and 3) indicate there is no unaltered version of any of the rock types identified in the Mazenod
Lake region. Despite the lack of unaltered rocks to choose from, there are several rock samples
that have been affected by only a relatively minor amount of hydrothermal alteration. These
‘least altered’ samples are used as the best representation of each rock type in the following
discrimination diagrams and mass balance analysis.
Least altered samples were selected based on their field descriptions and a visual
inspection for most of the selected samples. Selected least altered rock types were then compared
for similarities in whole-rock chemistry (with emphasis on major element oxides). Rocks with
significant deviations from the average concentration of elements in a least altered rock were
considered hydrothermally altered and not acceptable as a standard representation of a leastaltered rock. Table 4 lists the samples selected as least altered representations of Mazenod
lithology and their corresponding geochemical data. For rock types that have multiple least
altered samples, an average of their whole-rock chemistry is used to represent a least altered
rock. Some rock types have only a single least-altered sample. Mass balance calculations that
include a single reference will have a greater potential for error than calculations that include an
average of several least-altered samples.

- 84 -

TABLE 4: Selected least altered representatives of lithology
Rock type

Least altered
selection
Al2O3
wt.%

CaO
wt.%

Fe2O3
wt.%

MgO
wt.%

MnO
wt.%

Element concentrations
P2O5
K2O
Na2O
wt.%
wt.%
wt.%

TiO2
wt.%

SiO2
wt.%

LOI
wt.%

Average1

15.93

3.74

5.85

2.13

0.14

0.11

4.21

3.13

0.61

61.67

2.67

98156

17.3

7.45

8.82

4.25

0.1

0.08

2.3

2.82

0.68

54.2

1.6

Dacite

98089

16.4

3.44

5.61

1.45

0.05

0.22

4.86

2.94

0.84

62.8

1.4

Rhyodacite

Average2

16

2.49

3.51

1.15

0.07

0.07

5.11

3

0.43

66.7

1.5

Monzodiorite

97078

16.1

2.8

3.18

0.94

0.07

0.07

4.99

3.27

0.42

67.4

0.9

Monzogranite

Average3

12.3

0.19

1.2

0.21

0.02

0.01

7.48

1.65

0.1

76.25

0.55

Ag ppm

As ppm

Au ppb

Ba ppm

Be ppm

Bi ppm

Cd
ppm

Ce ppm

Co ppm

Cr ppm

Cs
ppm

Cu
ppm

Dy
ppm

Average1

<0.1

6.8

3

820

2.1

0.3

<0.1

77

16.6

92

4.4

33.6

3.98

98156

<0.1

4.6

<2

248

2.1

0.3

<0.1

43

20.9

175

1.4

5

2.87

Andesite
Basaltic
Andesite

Andesite
Basaltic
Andesite
Dacite

98089

0.2

5.5

<2

867

2.6

0.1

0.2

106

10.1

73

2.4

18.2

5.47

Rhyodacite

Average2

0.35

6.67

4

979

2.3

0.43

0.2

93

6.2

99.7

2.1

18.23

3.99

Monzodiorite

97078

<0.1

4.8

<2

908

2.4

0.3

0.2

88

5.2

129

1.6

9.6

3.78

Monzogranite

Average3

0.41

0.88

1

235.5

2.7

0.23

<0.1

61

1.9

160.3

1.35

9.23

3.79

Er ppm

Eu ppm

Ga ppm

Gd ppm

Ge ppm

Hf ppm

Hg
ppm

Ho ppm

La ppm

Lu ppm

Mo
ppm

Nb
ppm

Nd
ppm

9

29.9

Andesite
Basaltic
Andesite

Average1

2.12

1.2

18.8

4.4

1.4

4.1

<0.1

0.99

39

0.3

1.5

98156

1.48

0.94

15.3

3.19

1.4

3.1

<0.1

0.66

21

0.2

1.3

5

19.2

Dacite

98089

2.66

1.76

19

6.17

1.5

7.6

<0.1

1.31

50

0.4

2.3

10

41

Rhyodacite

Average2

2.12

1.35

17.73

4.53

1.33

5.60

0.23

0.95

49

0.37

1.9

9.7

33.17

Monzodiorite

97078

2.07

1.25

15.5

4.35

1.2

5.9

<0.1

0.88

46

0.4

1.5

10

31.4

Monzogranite

Average3

2.18

0.36

13.03

3.55

1.38

3.75

<0.1

0.91

29.25

0.43

1

21.5

21.98

- 85 -

Ni ppm

Pb ppm

Pr ppm

Rb ppm

Sb ppm

Sc ppm

Se ppm

Sm ppm

Sn ppm

Sr ppm

Ta
ppm

Tb
ppm

Te
ppm

Andesite
Basaltic
Andesite

Average1

13

12.3

9.06

209

4

13

<1

5.28

<0.1

195

1.82

0.7

<0.1

98156

39

5.7

5.13

146

1

23

<1

3.73

6.3

203

0.75

0.47

<0.1

Dacite

98089

10

17.2

12.1

176

5

11

<1

7.29

2.3

231

1.61

1

0.1

Rhyodacite

Average2

19

21.13

10.14

194

1.3

7

0.67

5.26

1.28

206

1.6

0.7

<0.1

Monzodiorite

97078

39

1.03

0.74

<0.1

9.44

18.4

9.89

173

1

7

<1

5.26

9.3

Monzogranite

Average3

7.75

10.33

6.92

298

0.75

1.25

0.5

4.19

0.86

38.75

4.49

0.61

0.06

Th ppm

Tl ppm

Tm ppm

U ppm

V ppm

W ppm

Y ppm

Yb ppm

Zn ppm

Zr ppm

Andesite
Basaltic
Andesite

Average1

21.4

<0.01

0.38

7.13

92

5

23.7

2.3

117

153

98156

9.48

<0.01

0.24

2.12

127

4

17.9

1.53

28

101

Dacite

98089

21.8

<0.01

0.51

6.69

57

6

29.7

2.8

42

257

Rhyodacite

Average2

22.03

<0.01

0.39

5.98

38.3

24

23.1

2.33

46

195

Monzodiorite

97078

21.9

<0.01

0.36

6.22

34

7

21.9

2.28

49

167

23.28

2.84

10

67

Average3

Monzogranite
43.83
0.01
0.43
11.62
3.75
2.75
1Andesite least altered element concentrations averaged from samples 96259, 96423 and 96309.
2Rhyodacite least altered element concentrations averaged from samples 98138, 96372 and 96320.
3Monzogranite least altered element concentrations averaged from samples 96443, 96444, 97055, 98151.

- 86 -

Geochemical Classification
Volcanic rock samples are analyzed and classified in this study based on comparison of
their chemical composition and the application of commonly used volcanic rock discrimination
diagrams. Classification of rock samples by geochemistry constrains the origin of rocks in the
Mazenod Lake area and is also useful for creating a baseline from which to calculate residual
alteration indices (RAI), described later in this chapter. All geochemical rock classifications are
complemented with field observations and petrographic analysis.
The Pearce (1996) volcanic rock trace element discrimination diagram is used to classify
rock types in this study (Figure 28a and 28b). The advantage of this classification over other
potential volcanic rock discrimination diagrams is that it uses elements that are known to be
relatively immobile in the Mazenod Lake hydrothermal system (discussed in following text);
consequently, rocks should plot in their correct composition field regardless of alteration. The
diagrams show that volcanic rock samples from the Mazenod Lake region have predominantly
intermediate to felsic chemical compositions. Some of the lithogeochemical data plotted in the
composition diagrams show a borderline intermediate to felsic composition, also some samples
originating from the same rock formations plot in both andesite and rhyodacite composition
fields. For these instances, the rock formations are categorized based on the abundance of
samples that plot within their respective composition fields. Based on the placement of the
plotted chemistry data and hand specimen analysis, four rock types are identified, which include
basaltic andesite, andesite, dacite and rhyodacite. Spatial distribution of the rock types
recognized in the Mazenod Lake region is illustrated in Figure 29.

- 87 -

Zr/TiO2

(a)

n=6
Nb/Y
Fe2O3t

(b)
Zr/TiO2

(c)

n = 711

n=6
Nb/Y

Na2O+K2O

MgO

Fig. 28. (a) Least-altered representative samples plotted on a multivariate, immobile trace-element
ratio volcanic rock discrimination diagram (Pearce, 1996). Samples are shown to have a variety of
compositions that ranges from intermediate to felsic. Dacite classification based on petrographic
observations of quartz phenocrysts. (b) Pearce (1996) volcanic rock discrimination diagram with all
volcanic rock samples plotted. The diagram shows a similar, although greater spread to the
geochemical data. Rocks within the same formation are grouped with their predominant
composition field, irrespective of individual placement within the diagrams. c) Least-altered
volcanic rocks geochemical data plotted on the AFM tectonomagmatic discriminatory diagram.
The plotted data collectively shows a fractionation trend that is consistent with the calc-alkaline
magma series.

- 88 -

Fig. 29. Geochemical discrimination of rocks from the Mazenod Lake area. Digital elevation data
courtesy of the Ministry of Natural Resources.

- 89 -

(a) Tectonomagmatic Classification
The (Na2O + K2O) vs Fe2O3t vs MgO (AFM) igneous rock classification diagram is
useful for constraining the tectonomagmatic origin of Mazenod Lake region rocks. In previous
work several authors have classified rocks from the Mazenod Lake region as calc-alkaline
(Gandhi, 1994; Gandhi et al., 200l; Skanderbeg, 2001; Kulla, 2004; Gandhi 2013). Evidence
from this study supports this interpretation from previous work. Least-altered volcanic rock
samples plotted on the AFM diagram (Fig. 28c) illustrate a fractionation trend that is consistent
with the interpretation of a calc-alkaline magma series.
(b) Trace Element Discrimination of Granitic Rocks
The most typically used diagram to classify granitoid rocks based on their source region
(and potentially tectonic setting) is from Pearce et al., (1984). This diagram uses composition
fields which are defined by characteristic trace element abundances from known tectonic
settings. Least-altered granitoid samples from the Mazenod Lake region plotted on the
discrimination diagram lie within the fields for syn-collisional granites (Syn-COLG) and
volcanic arc granites (VAG) (Fig. 30).

Element Mobility
Stanley and Madeisky (1994) define an immobile element as an element that is neither
significantly added nor removed from a rock during metasomatism because of the elements low
solubility in aqueous fluids. Typically recognized immobile elements usually include Al and
High Field Strength Elements (HFSE) such as Ti, Zr, Hf, Nd, Y and/or Nb. These elements are
often useful for classifying rock types and determining mass changes because their
concentrations are not affected by hydrothermal additions and depletions. The ratios of immobile

- 90 -

Rb (ppm)

Nb (ppm)

Monzodiorite point overlap

Y (ppm)

Y + Nb (ppm)

Fig. 30. Granite discrimination diagrams from Pearce et al. (1984). Selected samples plot in the fields
for syn-collisional granites (Syn-COLG) and volcanic arc granites (VAG). The monzodiorite plots in
the same location as a monzogranite on the left diagram (they overlap). Geochemical data for samples
used as tetctonic classifiers are listed in Table 5. The red line on the right hand diagram is the upper
limit for some known ocean ridge granites (ORG). N=5.

elements for different rock types tend to plot in clusters on bivariate and multivariate diagrams.
Also, the immobile elements tend to plot along linear trends on binary diagrams that compare
element concentration differences between unaltered and hydrothermally altered rocks.
There are several commonly used methods in related literature to determine immobile
elements, including: using typical immobile elements, comparing correlation coefficients for
element pairs, or observing a cluster of slope values of several element pairs then selecting an
average from the selected slope values (MacLean and Kranidiotis, 1987; Cail and Cline, 2001;
Grant, 2005). In this study, Zr and Hf were chosen as immobile elements. These elements are
mainly associated with the mineral zircon, which is typically not affected by hydrothermal
alteration. Aluminum is also recognized as an immobile element because it has been
demonstrated as immobile in similar studies of IOCG hydrothermal systems (Montreuil et al.,
2016) and has a moderately high correlation coefficient with Zr (r=0.53, n=707). For analytical

- 91 -

purposes, Al2O3 and Zr are preferentially used in the quantitative analysis of the geochemical
data instead of Hf because the elements have a higher concentration within the rocks;
consequently, they are less prone to error in the following examination.
Binary elemental plots can be used to analyze the mobility of elements in a hydrothermal
system. The diagrams shown in Figure 31 compare elements that are known to be typically
immobile against Zr. In general, there is a positive correlation and linear relationship between the
typically recognized immobile elements and Zr. Although the significance of each relationship
varies, the diagrams demonstrate that these elements have a relatively similar immobile
behaviour in the altered volcanic rocks from the Mazenod hydrothermal system.
Binary diagrams shown in Figure 32 illustrates the relationship of several major elements
to Zr. In general, samples that have lower concentrations of Zr have a greater variation in major
element oxide content, but this may be due to analytical error arising from the low Zr values.
Potassium concentrations ranges from almost 0 to 12.8 wt.%, and Na2O from almost 0 to 9.7 wt.
%. Compared to the average K2O and Na2O content of a typical unaltered calc-alkaline andesite
(usually the concentrations are in the range of ~3 ± 0.5 wt.%), the rocks from the Mazenod
hydrothermal system demonstrate significant variation in these element concentrations. In
contrast, P2O5 and SiO2 have a relatively restricted variation in their concentration with respect
to Zr, which indicates these elements are less mobile. The other major elements appear to be
moderately (or selectively) mobile. There does not appear to be any correlation between rock
type and degree of element mobility.

- 92 -

r = 0.48

Y
(ppm)

r = 0.38

r = 0.93

Nd
(ppm)

Hf
(ppm)

r = 0.41

r = 0.53

Al2O3
(wt.%)

Th
(ppm)

r = 0.53

r = 0.60

Nb
(ppm)

TiO2
(wt.%)

Zr (ppm)

Zr (ppm)

Fig. 31. Binary diagrams illustrating the relationship between elements that are typically immobile in
hydrothermal systems (n=707). In general, The Zr-Hf plot is the most useful diagram for distinguishing
unique rock formations and the Ti-Zr diagram for discriminating rock types. Several significant outliers
have been removed to ease visual interpretation of the geochemical data.

- 93 -

r = -0.06

SiO2
(wt.%)

r = -0.21

MnO
(wt.%)

r = 0.53

P2O5
(wt.%)

r = 0.32

K2O
(wt.%)

r = 0.08

Na2O
(wt.%)

r = -0.31

MgO
(wt.%)

r = -0.18

r = -0.20

Fe2O3
(wt.%)

CaO
(wt.%)

Zr (ppm)

Zr (ppm)

Fig. 32. Binary diagrams illustrating the relationship between major element oxides (wt. %) and Zr
(ppm) (n=707). Elements that have a greater distribution in the vertical axis such as K2O and Na2O are
the most mobile elements in the Mazenod hydrothermal system. Elements that do not have a significant
vertical spread, such as SiO2 and P2O5 are less mobile. Several significant outliers have been removed to
ease visual interpretation of the geochemical data.

- 94 -

Mass Balance Analysis
There are several methods that can be used to evaluate chemical gains and losses that
result from hydrothermal alteration (Gresens, 1967; Grant, 1986; MacLean and Barrett, 1993;
Stanley and Madeisky, 1996). For this thesis, the isocon method developed by Grant (1986) is
used to quantitatively assess chemical changes in the rocks. This is a simplified form of Gresens
(1967) analytical approach for evaluating mass change. The isocon method also eliminates the
need to apply complex mathematical methods in favor of a relatively simple graphical solution.
In the isocon method, elements of an altered rock (Y-axis) and elements from an
unaltered rock (X-axis) are plotted in a binary diagram. A linear line is constructed through the
origin and elements that are immobile. Consequently, the immobile elements lie upon a line of
constant mass (the isocon, no mass change during hydrothermal alteration) within the binary
diagram. The slope of the isocon defines whether the rock has experienced a net mass gain
(addition) or loss (removal). If the slope of the isocon is >1 (i.e. >45°) the rock has experienced
a loss in mass, and if the slope is <1 (i.e. <45°) the rock has gained in mass. Elements that are
plotted above the isocon have gained in concentration and elements below have experienced
depletion during alteration. The element concentration changes are quantified relative to the
slope of the isocon. Equations used to determine concentration and mass changes are listed in
Appendix 2 and resulting calculations for all the mass balance analysis completed for this study
are listed in Appendix 5, Table 11. Figure 33 shows the spatial location of where the mass
balance tested samples were originally collected and petrographic observations of the selected
samples are discussed in Appendix 3, Table 10.

- 95 -

Site 1

Site 2

Site 4

Site 3

Fig. 33. Location map showing where lithogeochemical samples originated that have been mass balance
analyzed for this thesis. Site locations reference the samples that are analyzed with the isocon diagrams.
Digital elevation data courtesy of the Ministry of Natural Resources.

- 96 -

Isocons of Mineralized Samples
Eight isocon diagrams were constructed with the use of lithogeochemical data from
selected mineralized samples and samples originating from locations of specific interest (Figs. 34
to 37). These analyzed samples contain varying but anomalous concentrations of Au, Cu, Bi, Co
and W, from Dan Island, Nod Hill, the Bea area, and an isolated area to the east of Nod Hill.
There are also visible sulphides and/or the oxidized mineral by-product of sulphides present in
the hand samples. For the purposes of this analysis, Al2O3 is considered an immobile element in
the mass balance testing.
(a) Site 1, Dan Island
The samples originating from Dan Island were collected from the same protolith and in
relative proximity to each other (~15 m). Both of the samples analyzed are characterized by a
moderate potassic alteration and the presence of sulphides. They show similar changes in
element concentrations with both samples being significantly enriched in K2O (avg. 154%) and
Fe2O3 (avg. 74%) (Figs. 34a, b). These rocks have also been significantly depleted in CaO, Na2O
and MnO (avg. -73%, -52% and -45%). Major elements that are relatively conserved during
alteration include SiO2, TiO2, and P2O5 (avg. 8%, -1% and -9%). Other significant concentration
changes for both samples include the depletion of Zn, Sr and Cs (avg. -58%, -66% and -34%) as
well as Bi, Ba and Rb enrichment (avg. 49,600%, 102% and 96%). No pattern of gains or losses
are apparent for the REEs. Sample 96217 shows a relatively minor depletion in REE content,
while the opposite is true for sample 96222. The trace element additions for sample 96217
occurred in the following decreasing order of percent change: Bi, As, Au, Co, Ag, Hg, Cu, W,
Sn, Lu, Yb, Tm, Sb, Ba, Ni, Rb, Cr, Er, Cd, Y, Ho, Hf, U, Eu, Dy, V, Th, Te, Zr, Sc, Ga,

- 97 -

Figs. 34a, b. Isocon diagrams graphically illustrating major element oxide and selected trace element
gains and losses within hydrothermally altered andesite ignimbrites northeast of Dan Island. Leastaltered andesite is the average of selected least-altered andesite samples (Table 5). Oxides are measured
in weight %, trace elements are in parts per million, except Au in parts per billion. The isocon line is
constructed assuming Al2O3 is immobile. Enriched elements plot above the line, depleted elements
below the line. All oxides and trace elements are factored in order to fit within the graph.

Figs. 35a, b. Isocon diagrams graphically illustrating major element oxide and selected trace element
gains and losses within hydrothermally altered andesite and rhyodacite ignimbrites. Sample locations
from near the percussion drilling sites that Noranda completed south of Dan Island and east of Nod hill.
The least-altered samples are the average of selected least-altered andesite samples (Table 5). Oxides
are measured in weight %, trace elements are in parts per million. The isocon line is constructed
assuming Al2O3 is immobile. Enriched elements plot above the line, depleted elements below the line.
All oxides and trace elements are factored in order to fit within the graph.

- 98 -

Tb. Trace element losses by increasing loss occurred for: Zn, Sr, Se, Mo, Cs, Tl, La, Pr, Nd, Ce,
Pb, Ta, Gd, Be, Ge, Sm. For sample 96222 the additions that took place are: Bi, As, Au, Hg, Co,
W, Te, Cu, Mo, Ni, Ba, Rb, Sb, Ce, Eu, La, Nd, Pr, Cr, Cd, Sm, Ga, Sn, Gd, Lu, Nb, Hf, Sc, U,
Pb, Ge, V, Th, Tb. The losses of sample 96222 include: Sr, Tl, Zn, Y, Ho, Cs, Dy, Tm, Er, Ta,
Be, Se, Zr, Yb. The two samples from Dan Island have a net mass increase of 12.21% and
10.65% respectively.
(b) Site 2, NE of Nod Hill
Two samples are mass balance analyzed from a location in moderate proximity to each other
north-east of Nod Hill (~84 m) (Figs. 35a, b). These samples were collected from two unique
andesite formations that have nearly equal distances from the contact that separates them. They
are both characterized by a minor presence of sulphides (pyrite and chalcopyrite) and magnetite.
Sample 97094 also contains veinlets of actinolite, and sample 97099 has a potassic alteration
overprint. Both samples are enriched in Na2O (avg. 177.98%) and depleted in K2O, CaO and
MnO (avg. -85%, -63% and -73%). The other major element oxides are relatively conserved,
although Fe2O3 and MgO show variable minor gains and losses, and P2O5 in sample 97094 has an
anomalous enrichment (44%). In sample 97094, trace element additions occurred in the
following order of decreasing percent change: Cu, Bi, Hg, W, Au, Ag, As, Te, Sn, Pr, Ce, Nd,
Sm, Cr, Tb, Gd, Dy, Lu, Er, Nb, Yb, Tm, Ho, Eu, Y, La, Hf, Be, Sb, U, Zr, Th, Ta and Ge.
Elements that are shown to be immobile or have little change in concentration include Se, Ga
and Co. Trace element losses occurred for Ni, Cd, Mo, Tl, Sc, Pb, V, Sr, Zn, Ba, Cs and Rb. In
sample 97099, trace element additions include Cu, Au, Bi, Sn, As, Cr, Be, Nb, Hf, Yb, Dy and
Nd. The mostly immobile elements include Y, Pr, Zr, Ag, Hg, U and Ni. Trace elements depleted
from hydrothermal alteration include Cs, Zn, Rb, Ba, Sr, Pb, W, Sb, Co, Cd, La, V, Mo, Th, Se,
- 99 -

Ce and Ta. There was a net mass gain of 16.28% (Fig. 35) and net mass loss of 4.02% (Fig. 36)
for the two samples, respectively.
(c) Site 3, Bea Area
Element gains and losses for the mineralized samples collected from the Bea area are
illustrated in Figures 36a, b. The two samples have a different protolith and are not from an area
near each other (~400 m apart), but have been described as having been similarly altered with
hematite, magnetite, quartz and minor sulphide hydrothermal minerals. Sample 97258
experienced a significant enrichment in Fe2O3 and MgO (217% and 20%) as well as depletion in
Na2O and CaO (-62% and -68%). Trace element gains arranged in order from greatest
enrichment include W, Hg, Sn, Co, Mo, As, Bi, Ni, Cu, Cr, U, V, Au and Se. Elements that have
been conserved include Al2O3, TiO2, Th, Zr, Hf, Sb and Ta. Trace elements depleted in order of
percent depletion includes Zn, La, Ce, Pr, Nd, Cs, Ag, Pb, Be, Sr, Cd, Dy and Rb. In sample
97249, most of the major elements are relatively conserved. There are only comparatively minor
gains in P2O5, K2O, SiO2, TiO2 and CaO (38%, 26%, 26%, 13% and 11%). Major elements
significantly depleted include MnO and MgO (-83% and -31%) along with minor depletions of
Fe2O3 and Na2O (-11% and -9%). Trace element gains in order of enrichment include Ag, Cu,
Au, Hg, Sn, W, Bi, U, Rb, Nb, Cr, Ta, As, Be, Co, Th, Ni, Hf and Zr. Trace element depletions
include Mo, Zn, Se, V, Sb, Ba, La, Pr, Ce, Y, Nd, Dy, Cd, Yb, Sr and Cs. Both samples gained in
mass, 22.39% (Fig. 37) and 17.16% (Fig. 38) respectively.
(d) Site 4, Nod Hill
Illustrated in Figures 37a and b are the isocon diagrams for samples collected from Nod
Hill. The two samples were collected approximately 277 m apart from each other in the central

- 100 -

Fig. 36a, b. Isocon diagrams graphically illustrating major element oxide and selected trace element
gains and losses within hydrothermally altered andesite and dacite ignimbrites located in the Bea area.
Least-altered andesite is the average of selected least-altered andesite samples (Table 5). Oxides are
measured in weight %, trace elements are in parts per million. The isocon line is constructed assuming
Al2O3 is immobile. Enriched elements plot above the line, depleted elements below the line. All oxides
and trace elements are factored in order to fit within the graph.

Fig. 37a, b. Isocon diagrams graphically illustrating major element oxide and selected trace element
gains and losses within hydrothermally altered rhyodacite ignimbrites located at Nod hill. Oxides are
measured in weight %, trace elements are in parts per million. The isocon line is constructed assuming
Al2O3 is immobile. Enriched elements plot above the line, depleted elements below the line. All oxides
and trace elements are factored in order to fit within the graph.

- 101 -

and southern portion of Nod Hill respectively. They are both characterized by a moderate
potassic alteration and are comprised of a minor amount of sulphides (pyrite and chalcopyrite)
and magnetite. Both samples have been moderately enriched in K2O, Na2O, Fe2O3 and SiO2
(avg. 41%, 52%, 48% and 16%) and have been depleted in MnO, CaO, TiO2, P2O5 and MgO
(avg. -85%, -82%, -20%, -24% and -70%). The two samples have many similarities in their trace
element enrichments and depletions. The REEs are variable, but have comparatively minor
enrichments and depletions. Both samples have gains in concentrations for Cu, As, Mo, Au, Cr,
Co, Ta, U and Th. Trace elements commonly depleted include Zn, Pb, Nb, Cd, Zr, Hf and Sr.
Both samples have gained in mass, 11.11% and 14.29%, respectively.

Quantitatively Assessing Hydrothermal Alteration
In this subsection of the thesis, different types of hydrothermal alteration are
distinguished by their own distinct chemical signatures. This information is crucial for
development of alteration indices, which quantifies the intensity of each alteration type
throughout the study region based on the unique chemical signature.
Enrichment-depletion diagrams are used to graphically demonstrate relative
concentration changes (mobility) of major and trace elements (Rollison, 1993). These diagrams
display multiple samples from different rocks in a similar arrangement to ease visual
interpretation. The x-axis of the diagram is adjusted such that it is equivalent to the isocon line,
with the assumption that Al2O3 is an immobile element. The bars parallel to the y-axis display
the relative percent change of chemical composition for a corresponding element listed at the
base of the x-axis. The maximum amount of percent change displayed on the diagram is 350%;
however, the actual amount of change can exceed this limit. Mass balance formulas used to
calculate percentage changes in element abundance are listed in Appendix 2. Petrographic
- 102 -

descriptions and classifications for each analyzed sample are listed in Appendix 3, Table 10.
Reported averages in this section are in percent element concentration change.
Samples selected to classify alteration were chosen based on a visual interpretation or by
a review of sample descriptions completed by geologists from BFR Copper & Gold. Most of the
samples chosen are classified as intensely altered of a certain alteration type and a few as
moderately altered. Samples were also preferentially selected for replacement-type alteration as
opposed to vein filling; however, several of the chosen samples do contain veins which have
some impact on results and following interpretations. Many of the selected samples analyzed by
this method have only one visible type of alteration affecting the rock although there are several
samples that have minor, yet discernible different alteration effects. As mentioned in Chapter 5,
there are regional, pervasive and early alkali alteration effects (predominantly potassic alteration)
to the rocks in the Mazenod Lake region that likely impact both K2O and Na2O concentration
gains and losses in many, if not all the samples mass balance analyzed.
(a) Magnetite ± Actinolite (MA) Alteration
Figure 38 illustrates the percent gains and losses in major and trace elements for selected
samples that contain MA (magnetite ± actinolite) alteration. Consistently depleted major element
oxides for these samples include MgO and MnO (avg. -47% and -41%). The main distinct
pattern in Na2O and K2O mobility is the relatively opposite trends of enrichment and depletion.
In samples enriched with Na2O, they are also depleted in K2O and vice versa. Conserved major
elements include SiO2 and TiO2 (avg. 5% and 1%). Calcium and iron oxide have a similar
correlation of their concentration changes but are variably enriched or depleted.

- 103 -

350
300
250
200
150
100
50
0
-50
-100

97005

97124

97129

98172

LOI

SiO2

TiO2

Na2O

K2O

P2O5

MnO

MgO

Fe2O3

CaO

Mean ∆Mass = 1.95%

Ge

Gd

Ga

Eu

Er

Dy

Cu

Cs

Cr

Co

Ce

Cd

Bi

Be

Ba

Au

As

Ag

350
300
250
200
150
100
50
0
-50
-100

Sb

Rb

Pr

Ni
U

Pb

Nd
Tm

Nb

Mo

Lu

La

Ho

Hf

Hg

350
300
250
200
150
100
50
0
-50
-100

Zr

Zn

Yb

Y

W

V

Tl

Th

Te

Tb

Ta

Sr

Sn

Sm

Se

350
300
250
200
150
100
50
0
-50
-100

Sc

Percent changes in major and trace element concentrations

97095

Fig. 38. Graphical illustration of calculated concentration changes for samples that have been
magnetite-actinolite (MA) altered. Aluminum is not listed, as it was used as a conserved element for
mass balance calculations. Absolute value results listed in Appendix 5, Table 11.

- 104 -

The higher amount of CaO enrichment in sample 97124 (186%) is probably influenced by the
minor presence of epidote observed in the sample. The trace elements typically enriched include
Sn, As, Cr and Ce. Trace elements depleted most often include Cs, Zn, Sr, Cd and Be. Conserved
trace elements include Zr, Hf, Tl, Ta and the HREEs. The rest of the trace elements have variable
minor to moderate trends in element gains and losses. Mass changes are variable for each of the
analyzed samples but shows an average gain of 1.95%.
(b) Potassic Alteration
Potassic altered samples are enriched in K2O (avg. 131%) and generally depleted in
Na2O, CaO, MgO and MnO (avg. -46%, -93%, -72% and -81%) (Fig. 39). Comparatively
conserved elements include Fe2O3, TiO2 and SiO2 (avg. -7%, -20% and 20%), whereas P2O5 is
variably enriched or depleted. Trace elements that have relatively constant enrichments include
Ba, Cr, Rb, Te, Th and U. Trace elements that are commonly depleted in these altered samples
include Be, HREEs, Mo, Nb, Nd, Ni, Pb, Sc, Sr, and Zn. Most of the remaining trace elements
show minor to moderate enrichment and depletion, with the exception of the immobile element
Zr. The mean mass change for the potassic altered samples is a gain of 12.58%.
(c) Tourmaline Alteration
Metasomatic rocks with abundant tourmaline exhibit a substantial range in element
mobility (Fig. 40). Samples representative of tourmaline alteration are mostly enriched in K2O
(avg. 71%). Major elements oxides that have comparatively minor gains in concentration
includes SiO2 and Fe2O3 (avg. 37% and 28%). Typically depleted elements include Na2O, CaO,
MnO and usually MgO (avg. -70%, -88%, -85%, and -16%, respectively). The only relatively
conserved major element oxides include TiO2 (avg. 8.82%). In contrast, P2O5 has a large
variance, with both gains and losses. Trace elements usually added to the tourmaline
- 105 -

350
300
250
200
150
100
50
0
-50
-100

96240

96239

97041

97123

LOI

SiO2

TiO2

Na2O

K2O

P2O5

MnO

MgO

Fe2O3

CaO

Mean ∆Mass = 12.58%

Ge

Gd

Ga

Eu

Er

Dy

Cu

Cs

Cr

Co

Ce

Cd

Bi

Be

Ba

Au

As

Ag

350
300
250
200
150
100
50
0
-50
-100

Sb

Rb

Pr

Ni
U

Pb

Nd
Tm

Nb

Mo

Lu

La

Hf

Hg

Ho

350
300
250
200
150
100
50
0
-50
-100

Zr

Zn

Yb

Y

W

V

Tl

Th

Te

Tb

Ta

Sr

Sn

Sm

Se

350
300
250
200
150
100
50
0
-50
-100
-150

Sc

Percent changes in major and trace element concentrations

96232

Fig. 39. Graphical illustration of calculated concentration changes for samples that have been potassic
altered. Aluminum is not listed, as it was used as a conserved element for mass balance calculations.
Absolute value results listed in Appendix 5, Table11.

- 106 -

350
300
250
200
150
100
50
0
-50
-100

96233
96233

97228
97266
96479
97228
97266
96479

LOI

SiO2

TiO2

Na2O

K2O

P2O5

MnO

MgO

Fe2O3

CaO

Mean Δmass = 24.50%

Ge

Gd

Ga

Eu

Er

Dy

Cu

Cs

Cr

Co

Ce

Cd

Bi

Be

Ba

Au

As

Ag

350
300
250
200
150
100
50
0
-50
-100

Sb

Rb

Pr

Ni
U

Pb

Nd
Tm

Nb

Mo

Lu

La

Ho

Hg

350
300
250
200
150
100
50
0
-50
-100

Hf

Percent changes in major and trace element concentrations

97227
97227

Mean ∆Mass = 23.94%

Zr

Zn

Yb

Y

W

V

Tl

Th

Te

Tb

Ta

Sr

Sn

Sm

Se

Sc

350
300
250
200
150
100
50
0
-50
-100

Fig. 40. Graphical illustration of calculated concentration changes for samples that have been tourmaline
altered. Aluminum is not listed, as it was used as a conserved element for mass balance calculations.
Absolute value results listed in Appendix 5, Table 11.

- 107 -

altered samples include Ag, As, Ba, Bi, Co, Cr, Hg, Mo, Rb, Sb, and W. Those elements mostly
depleted include Be, Ce, Cu, Pb, Cs, REEs, Sr and Zn. Trace elements that have the least
concentration changes include Zr, U, Th, Se, Ta and Tl. The rest of the elements have no
identifiable trend. The average change in mass is a gain of 23.94%.
(d) Propylitic Alteration
Figure 41 illustrates the percent concentration changes for several propylitic
metasomatized samples. These samples contain abundant epidote and often contain chlorite and
carbonate alteration minerals. Changes are generally minor and there is very little consistency in
the pattern of gains and losses of major element oxides, other than that SiO2 remains mostly
unchanged. Trace elements usually added to the rocks due to alteration include Bi, REEs, Cu, Sb
and Sr. The only trace elements usually removed during alteration includes Au, Ni and Cs. Trace
elements that are mostly conserved despite alteration include Ag, Ga, Hf, Nb, Sc, Te, Th, Tl, Y
and Zr. The remaining elements are variably enriched or depleted. The average mass change for
these samples is a gain of 1.14%.
(e) Hematite Alteration
Figure 42 shows the percent concentration changes of several hematite altered samples.
Sample 97063 contains abundant vein material and is therefore excluded in the following
discussion and listed average concentration changes. Hematite altered samples are predominantly
enriched in Fe2O3 (avg. 266%). Most samples have also been enriched in MgO, MnO and lesser
K2O (avg. 116%, 90%, and 63%), while Na2O is consistently depleted (avg. -78%). Major
elements are generally depleted include CaO and P2O5. Comparatively conserved during
alteration are TiO2 and SiO2 (avg. -21% and 15%). The trace elements usually enriched include

- 108 -

350
300
250
200
150
100
50
0
-50
-100

97080

96386

98191

98185

LOI

SiO2

TiO2

Na2O

K2O

P2O5

MnO

MgO

Fe2O3

CaO

Ge

Gd

Ga

Eu

Er

Dy

Cu

Cs

Cr

Co

Ce

Cd

Bi

Be

Ba

Au

As

Ag

350
300
250
200
150
100
50
0
-50
-100

Sb

Rb

Pr

Ni
U

Pb

Nd
Tm

Nb

Mo

Lu

La

Hg

Ho

350
300
250
200
150
100
50
0
-50
-100

Hf

Percent changes in major and trace element concentrations

98271

Mean ∆mass = 1.14%

Zr

Zn

Yb

Y

W

V

Tl

Th

Te

Tb

Ta

Sr

Sn

Sm

Se

Sc

350
300
250
200
150
100
50
0
-50
-100

Fig. 41. Graphical illustration of calculated concentration changes for samples that have been propylitic
altered. Aluminum is not listed, as it was used as a conserved element for mass balance calculations.
Absolute value results listed in Appendix 5, Table 11.

- 109 -

350
300
250
200
150
100
50
0
-50
-100

96238

96227

97063

97254

LOI

SiO2

TiO2

Na2O

K2O

P2O5

MnO

MgO

Fe2O3

CaO

Mean ∆mass = 684%
(with sample 97063 removed,
mean ∆mass = 32.32%)

Ge

Gd

Eu
Y

Ga

Er
W

Dy

Cu

Cs

Cr

Co

Ce

Cd

Bi

Be

Ba

Au

As

Ag

350
300
250
200
150
100
50
0
-50
-100

Sb

Rb

Pr

Pb

Ni

Nd

Nb

Mo

Lu

La

Ho

Hg

Hf

350
300
250
200
150
100
50
0
-50
-100

Zr

Zn

Yb

V

U

Tm

Tl

Th

Te

Tb

Ta

Sr

Sn

Sm

Se

350
300
250
200
150
100
50
0
-50
-100

Sc

Percent changes in major and trace element concentrations

96405

Fig. 42. Graphical illustration of calculated concentration changes for samples that have been hematite
altered. Aluminum is not listed, as it was used as a conserved element for mass balance calculations.
Absolute value results listed in Appendix 5, Table 11.

- 110 -

Hg, Cr, Ga, Ge, Sn, Te, Tl, and W. Those trace elements typically depleted include Cs, Pb, Sr,
Th and Zn. Trace elements that remain comparatively unchanged from alteration include Th and
Ta. The remaining elements are variably enriched or depleted. Mass change for these samples is
variable, although they all have increased in mass from the hydrothermal alteration. The average
mass gain (not including sample 97063) is 32.32%
(f) Silicification
Most of the silicified samples have gained significant SiO2 (avg. 736%) (Fig. 43). The
major element oxides removed from the host rocks usually include CaO and Na2O (avg. -55%
and -50%) and in lesser amounts TiO2 and P2O5 (avg. -22% and -20%). The other major
elements have variable trends in their gains or losses. Trace elements usually gained in the
selected silicified samples include Ag, As, Au, Bi, Cu, Hg, Mo, Nb, Nd and Te. The trace
elements typically lost in these samples include Eu and Sr. Relatively conserved trace elements
include Hf, Ta, Th, U, W, Zr and most REEs. The remaining elements are variably enriched or
depleted.

Alteration Indices
The final geochemical analysis is the development and testing of alteration indices (AIs)
and residual alteration indices (RAIs) using techniques originally developed by Ishikawa (1974)
and Mumin (1988), respectively. The AI is useful for quantifying relative intensity of alteration
within a specified rock type of uniform chemical composition and determining chemical alteration
patterns that are not manifest as changes in mineralogy. Each AI represents an alteration type
and/or element enrichment that is scaled in relative intensity based on the concentration of
elements added and removed from the rock. Alteration indices are calculated using the following

- 111 -

350
300
250
200
150
100
50
0
-50
-100

96427

98032

98207

96392

LOI

SiO2

TiO2

Na2O

K2O

P2O5

MnO

MgO

Fe2O3

CaO

Mean ∆mass = 462%
(with samples 98032 and 97030
removed mean ∆mass = -1.3%)

Ge

Gd

Ga

Eu

Er

Dy

Cu

Cs

Cr

Co

Ce

Cd

Bi

Be

Ba

Au

As

Ag

350
300
250
200
150
100
50
0
-50
-100

Sb

Rb

Pr

Pb

Ni

Nd

Nb

Mo

Lu

La

Ho

Hf

Hg

350
300
250
200
150
100
50
0
-50
-100

Zr

Zn

Yb

Y

W

V

U

Tm

Tl

Th

Te

Tb

Ta

Sr

Sn

Sm

Se

350
300
250
200
150
100
50
0
-50
-100

Sc

Percent changes in major and trace element concentrations

97030

Fig. 43. Graphical illustration of calculated concentration changes for samples that have been silicified.
Aluminum is not listed, as it was used as a conserved element for mass balance calculations. Absolute
value results listed in Appendix 5, Table 11.

- 112 -

general equation:
𝐴𝑙𝑡𝑒𝑟𝑎𝑡𝑖𝑜𝑛 𝐼𝑛𝑑𝑒𝑥 (𝐴𝐼) =
(1)

𝑆𝑢𝑚 𝑜𝑓 𝐸𝑙𝑒𝑚𝑒𝑛𝑡𝑠 𝑎𝑑𝑑𝑒𝑑 𝑑𝑢𝑟𝑖𝑛𝑔 𝑎𝑙𝑡𝑒𝑟𝑎𝑡𝑖𝑜𝑛

(𝑆𝑢𝑚 𝑜𝑓 𝐸𝑙𝑒𝑚𝑒𝑛𝑡𝑠 𝑠𝑢𝑏𝑡𝑟𝑎𝑐𝑡𝑒𝑑 (𝑜𝑟 𝑐𝑜𝑛𝑠𝑒𝑟𝑣𝑒𝑑) 𝑎𝑛𝑑 𝑎𝑑𝑑𝑒𝑑 𝑑𝑢𝑟𝑖𝑛𝑔 𝑎𝑙𝑡𝑒𝑟𝑎𝑡𝑖𝑜𝑛) 𝑥 100%
The RAI calculation is a method for removing the effect of different host rock
compositions on the alteration index (Mumin, 1988). It allows comparison between rocks of
different initial composition and sets the measured alteration intensity scale from 0% – 100% for
all samples analyzed. Intensity of alteration is measured from 0% (no detectable alteration) to
100% (the maximum possible alteration effect according to a particular AI). To remove the
effect of variable host rock composition on the AI, a base index (BI) is subtracted. The BI is the
alteration index applied to the least altered rock version of each geochemically distinct rock type
(Table 5). The range of the index is constrained by dividing the AI-BI by 100 minus BI. For
clarity in plotting and interpretation, any result of the RAI that is below zero is converted to a
zero value since there is no ‘negative’ alteration. The equation is as follows:
(2)

𝑅𝐴𝐼 =

𝐴𝐼 − 𝐵𝐼
𝑥 100%
100 − 𝐵𝐼

For developing the AI formulae, preference in choosing variables is given to the major
element oxides. These are the most abundant elements within rocks and so best reflect
hydrothermal alteration. Only those rocks that have a least altered representation (listed in Table
4) are analyzed in this method. Table 5 lists the unique alteration types and the RAI formula that
have been applied to them.
The calculated results are shown as bubble plots and as interpolated surfaces (contoured)
overlaid on a map of the Mazenod Lake area in Figures 44 to 55. The simple kriging method
within ArcMap software is used to construct the contoured maps. This method is an advanced

- 113 -

TABLE 5. Residual Alteration Indices (RAIs) applied to the Mazenod Lake region.
Residual
Alteration
Index
Sodium
Enrichment

Element Ratios
[Na2O/(Na2O+Al2O3)]

Alteration Process
Na2O enrichment, Al2O3
conserved

Figures
44 & 45

Iron
Enrichment

[Fe2O3/(Fe2O3+Al2O3)]

Fe2O3 enrichment, Al2O3
conserved

46 & 47

Ca-Fe
Enrichment

[(CaO+Fe2O3)/(CaO+
Fe2O3+ K2O)]

48 & 49

Potassic I

[K2O/(K2O+Na2O+
MgO+MnO+CaO)]

Potassic II

[K2O/(K2O+Na2O)]

Addition of CaO and Fe2O3 as
magnetite-actinolite and/or
chlorite-epidote-carbonate as
well as depletion of K2O from
replacement of feldspars
Addition of K2O as K-feldspar,
depletion of Na2O, CaO, MgO
and MnO from replacement of
ferromagnesium and Na-rich
feldspars
Addition of K2O as K-feldspar,
depletion of Na2O from
replacement of Na-rich
feldspars

Silica
Enrichment

[SiO2/(SiO2+Al2O3)]

SiO2 enrichment, Al2O3
conserved

54 & 55

Source

50 & 51

52 & 53

Sericite
Index from
Saeki & Date
(1980)

geostatistical procedure that calculates values between known quantities and creates a twodimensional prediction surface (map). The predicted values that the kriging algorithm calculates
are a weighted average, based on modeling of a semivariogram graph. A complete explanation of
kriging methodology is beyond the scope of this thesis. For an overview of the process involved
in creating surfaces using the kriging technique, it is recommended to see the ArcGIS help file,
available online at: http://desktop.arcgis.com/en/arcmap/10.3/guidebooks/extensions/geostatistical-analyst/understanding-how-to-create-surfaces-usinggeostatistical-techniques.htm. Kriging parameters used to customize the surfaces are included in
the metadata accompanying the digital map files. Since the contours of the RAIs in some cases

- 114 -

correlate with mineralogy in outcrops, to a rough degree they can be corroborated by field
observations to determine relative accuracy of the RAI.
Only those alteration types that have predictable geochemical enrichment and/or
depletion patterns are used to calculate RAIs. For example, tourmaline alteration has no
consistent enrichment or depletion pattern (other than potentially B-enrichment, which is not
included in the geochemical analysis package). Consequently, no effective RAI could be
constructed for identifying areas and intensity of tourmaline alteration.

Residual Alteration Indices
(a) Sodium Enrichment Index
The sodium AI is defined by the equation Na2O/Na2O+Al2O3. Highest percent values of
the sodic RAI have the highest amount of Na2O enrichment (Figs. 44 and 45). These maps
represent a gauge of the intensity of Na2O gains throughout the Mazenod Lake region, with the
assumption that Al2O3 is immobile during hydrothermal alteration. Despite the small degree of
sodium enrichment, the RAI plots indicate that there are previously unrecognized sodic alteration
zones at the north end of Nod Hill and at the south end of the Bea area. Other more isolated
zones of Na-enrichment are spread throughout the area.
(b) Iron Alteration Index
Iron enrichment RAI is an indication of the extent of the intensity of iron enrichment
relative to the immobile element aluminum (Figs. 46 and 47). The AI is defined by the equation
Fe2O3/(Fe2O3+Al2O3). It is included in this thesis because iron is a major metal typically
associated with IOCG-type deposits and systems (Hitzman et al., 1992). The iron enrichment

- 115 -

Fig. 44. Bubble plot map that illustrates the distribution of sodium enrichment intensity (in %). Gradient
in color and size of points indicates changes in the amount of sodium enrichment relative to the immobile
element aluminum. Digital elevation data courtesy of the Ministry of Natural Resources.

- 116 -

Fig. 45. Interpolated prediction surface that illustrates the distribution of sodium enrichment intensity (in
%). Contours show a gradient of the amount of sodium enrichment relative to the immobile element
aluminum. Digital elevation data courtesy of the Ministry of Natural Resources.

- 117 -

Fig. 46. Bubble plot map that illustrates the distribution of iron enrichment intensity (in %). Gradient in
color and size of points indicates changes in the amount of iron enrichment relative to the immobile
element aluminum. Digital elevation data courtesy of the Ministry of Natural Resources.

- 118 -

Fig. 47. Interpolated prediction surface that illustrates the distribution of iron enrichment intensity (in %).
Contours show a gradient of the amount of iron enrichment relative to the immobile element aluminum.
Digital elevation data courtesy of the Ministry of Natural Resources.

- 119 -

RAI maps show many individual and local groupings with Fe-enrichment. There is a distinct
zone of iron enrichment surrounding Dan Island (particularly in the NW and SE) and locally at
Nod Hill. In the Bea area, there are subtler anomalies that are mostly grouped close together.
These observations tend to be coincident with areas noted in the field with relatively abundant
hematite and/or magnetite alteration minerals. There are also a few areas with outcrops that
contain moderate amounts of these minerals and show little or no enrichment on the RAI maps,
which indicates this magnetite is not a result of hydrothermal alteration (such as the magnetitebearing dacite ignimbrite). These RAI maps are an indication of the regional influence of iron
enrichment across the Mazenod Lake region.
(c) Ca-Fe Alteration Index
The MA RAI (Figs. 48 and 49) scales the intensity of calcium and iron enrichment as
well as potassium depletion. This is intended to coincide with the alteration process that involves
replacement of host rock minerals (mostly feldspars) by magnetite and actinolite. However, in
general, the high values of MA RAI index maps are an indication of the relative abundance and
distribution of iron plus calcium-rich minerals, which can include actinolite, magnetite, chlorite,
epidote and carbonate. The AI is represented by the equation
[(Fe2O3+CaO)/(Fe2O3+CaO+K2O)]. High MA RAI values (>61%) mostly correlate with rock
samples that contain actinolite ± magnetite; however, the mid-range values (<61% - 10%) are
quite often associated with epidote altered samples and even some tourmaline altered samples.
The very highest MA RAI values can be linked directly to actinolite cemented hydrothermal
breccias, such as at the northern end of Nod Hill. There are a few exceptions, including the far

- 120 -

Fig. 48. Bubble plot map that illustrates the distribution of Ca-Fe enrichment intensity (in %). Gradient in
color and size of points indicates changes in the amount of iron and calcium enrichment as well as
potassium depletion. Digital elevation data courtesy of the Ministry of Natural Resources.

- 121 -

Fig. 49. Interpolated prediction surface that illustrates the distribution of Ca-Fe enrichment intensity (in
%). Contours show a gradient for the amount of iron and calcium enrichment as well as potassium
depletion. Digital elevation data courtesy of the Ministry of Natural Resources.

- 122 -

north eastern and western portions of the contour map. At these locations, higher intensity
contours overlap with areas noted to contain abundant epidote alteration minerals. Contextual
field observations are necessary to differentiate between zones containing the different alteration
minerals.
(d) Potassic Alteration Indices
Two potassium RAI K2O/(K2O+Na2O) and K2O/(K2O+Na2O+CaO+MgO+MnO) are
plotted in Figures 50 to 53. The former RAI is a simple test for intensity of potassium enrichment
and sodium depletion, typically associated with crystallization of K-feldspar and replacement of
plagioclase (Benevides et al., 2008). Similarly, the latter potassic RAI tests for the same result,
but in addition include the effects of the removal of calcium, magnesium and manganese, due to
the replacement of ferromagnesium minerals by K-feldspar as well. The highest values of this
index may correlate with felsite-like K-altered rocks.
The potassic indices indicate the most widespread and intense hydrothermal alteration of
any index plotted. This matches field observations noted in Chapter 5 that suggested potassic
alteration is near ubiquitous in the study area. The highest values are located near the center and
highest elevated part of Dan Island, in proximity to the NE-oriented Kemaz fault. Another
distinctive grouping of higher potassic RAIs values occurs at Nod Hill and in the central Bea
area. These three distinctive potassic RAI anomalies also correspond with the intersections of
known faults.
Size of the K-alteration halos surrounding the highest potassic RAI values show that the
alteration can extend for several kilometers away from the potential foci of hydrothermal
alteration. The K-alteration plots demonstrate the spatially extensive area affected by
hydrothermal alteration.
- 123 -

Fig. 50. Bubble plot map that illustrates the distribution of potassic alteration intensity (in %). Gradient in
color and size of points indicates changes in the amount of potassic enrichment as well as sodium,
calcium, magnesium and manganese depletion. Digital elevation data courtesy of the Ministry of Natural
Resources.

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Fig. 51. Interpolated prediction surface that illustrates the distribution of potassium alteration intensity (in
%). Contours show a gradient for the amount of potassic enrichment as well as sodium, calcium,
magnesium and manganese depletion. Digital elevation data courtesy of the Ministry of Natural
Resources.

- 125 -

Fig. 52. Bubble plot map that illustrates the distribution of potassic alteration intensity (in %). Gradient in
color and size of points indicates changes in the amount of potassic enrichment and sodium depletion.
Digital elevation data courtesy of the Ministry of Natural Resources.

- 126 -

Fig. 53. Interpolated prediction surface that illustrates the distribution of potassium alteration intensity (in
%). Contours show a gradient for the amount of potassic enrichment and sodium depletion. Digital
elevation data courtesy of the Ministry of Natural Resources.

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(c) Silica Alteration Index
The silica enrichment RAI maps characterize the spatial extent of silica enrichment
intensity (i.e. silicification), with the assumption that aluminum is immobile during the alteration
(Figs. 54 and 55). Equation for the silica AI is SiO2/(SiO2+Al2O3). There are several giant
quartz-vein-silicification complexes present in the Mazenod Lake area, which represent an
extreme form of silica enrichment. These are largely vein complexes recorded during mapping,
so they are excluded from the RAI analysis.
Mid to high range silica RAI values (41% and greater) mostly coincide with field
observations of silicification. These high value anomalies have surrounding lower silica
enrichment RAI values (usually 15% or less), which do not match areas visually observed to
contain silicification. This indicates that silica alteration extends further that what can be
observed directly in outcrops and that the contours of the silica RAI represent a gradation of
silica alteration intensity.
In the vicinity of Mazenod Lake, there is a subtle silica RAI anomaly at Dan Hill (slightly
higher values in the rhyodacite). Along Net Ridge, there are several high silica RAI anomalies,
which are in accord with field observations of silicification along the Marian River fault at that
location (in the volcanic rocks), and are in spatial proximity to a giant quartz-vein complex.
Silica RAI values are also subtly higher across most of Nod Hill, with highest values in the
northern portion of the hill. These values correlate with actinolite-quartz ± magnetite veins and
breccia. The potassic RAI contours are arranged comparatively similarly within the extent of
Nod Hill. At the Bea area the silica and potassic RAI values instead have an almost inverse
relationship. High silica RAI values mostly correspond with low potassic RAI values at the same
coordinates in the Bea area. Many of the other regional high silica RAI anomalies are relatively

- 128 -

isolated as compared to the previously mentioned locations. Most of these anomalies are
proximal to locally recognized faults and/or hydrothermal breccias.

- 129 -

Fig. 54. Bubble plot map that illustrates the distribution of silica enrichment intensity (in %). Gradient in
color and size of points are intended to indicate changes in the amount of silica enrichment relative to the
immobile element aluminum. Digital elevation data courtesy of the Ministry of Natural Resources.

- 130 -

Fig. 55. Interpolated prediction surface that illustrates the distribution of silica enrichment intensity (in
%). Contours show a gradient for the amount of silica enrichment relative to the immobile element
aluminum. Digital elevation data courtesy of the Ministry of Natural Resources.

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Chapter VIII: Discussion
The Mazenod Lake region is underlain by early Proterozoic volcanic, sedimentary and
intrusive rocks, with younger Phanerozoic sedimentary rocks occupying part of the central and
western portion of the study area. The study area is dominated by volcanic rocks that are mostly
pyroclastic flows (ignimbrites), typical of stratovolcanic terrains. Least hydrothermally altered
versions of these volcanic rocks are usually dark grey, massive, undeformed and often eutaxitic.
Textures of the volcanic rocks include porphyritic, intergranular, inequigranular, seriate,
trachytic, corroded, and/or poikilitic types. The typical ignimbrites are crystal tuff, but the
volcaniclastic facies comprise tuffs, lapilli, ash, and pyroclastic breccias (Fisher, 1966). Each
volcanic rock formation varies slightly in mineral composition and vol. %, but usually contains
phenocrysts of potassium feldspar, plagioclase, biotite, quartz, pyroxene, and/or amphiboles. The
chemical classifications indicate they are calc-alkaline intermediate to felsic volcanic rocks.
The intrusive rocks are chemically similar to the volcanic rocks. They include deepseated and near surface expressions, such as the Marian River monzogranite batholith and a
monzodiorite intrusion, respectively. These plutonic rocks constrain and/or intrude into the
volcanic belt. The intrusive rocks have typically an orange-red hue at weathered surface, with
textures that are medium to coarse grained and feldspar-phyric. Intrusive dykes cross-cut the
volcanic belt, are spatially intermittent and generally are oriented sub-parallel to NE-trending en
echelon faults.

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Volcanic sediments predominantly comprised of reworked volcanic tephra and other
lithic fragments unconformably lie above most volcanic rock formations. Various facies of the
sedimentary rocks include well-preserved beds of claystones, sandstones and conglomerates. A
separate sequence of much younger Paleozoic era marine transgression sediments is discordant
and unconformably overlie all the other rocks in the region.

Stratigraphy
Exposed stratigraphy at and around Mazenod Lake portrays a succession of
Paleoproterozoic volcanic events that comprise several intermediate to felsic ignimbrite flows.
Local igneous rocks belong to the Faber Group, a subdivision of the McTavish Supergroup
Gandhi et al., 2001; Hildebrand et al., 2010). Volcanism commenced ca. 1873 Ma and lasted for
a period of approximately 7 million years (Gandhi and van Breemen, 2005; Montreuil et al.,
2016). Locally, extrusive events commenced with the emplacement of the Mazenod Lake
assemblage and sequentially continued with the eruption, deposition and consolidation of the
Bea Lake, Squirrel Lake, Lou Lake and Dianne Lake assemblages. During periods of volcanic
dormancy autochthonous sedimentary material was deposited and unconformably separated the
volcanic assemblages (Gandhi et al., 2001). Synchronous with the volcanic events a porphyritic
monzodiorite intruded and was emplaced in the region (Figs. 8-10). This intrusion is a likely
source intrusion for the region, and is presently mostly exposed along the southeastern shoreline
of Mazenod Lake and near Dan Island. The monzodiorite is interpreted to be an early expression
of the deep-seated Marian River Batholith monzogranite and/or the Sarah Lake granite. The deep
seated plutonic rocks have been dated at 1866 – 1863 Ma (Gandhi et al., 2001).
After volcanic activity, during the Paleozoic era, a layer of sedimentary strata was
unconformably deposited over large sections of volcano-plutonic rocks within the Mazenod Lake

- 133 -

area and the rest of the GBMZ (Hildebrand and Bowring, 1984; Hoffman, 1987; Gandhi et al.,
2001).

Structure
The geotectonic framework of the Mazenod Lake region is characterized by several sets
of subparallel linear and curvilinear faults and deformation zones. In Chapter 6, many of the
aforementioned structural features have been shown to form lineaments well-defined on satellite,
aeromagnetic and digital elevation images. A visual inspection of the lineaments reveals a
complex strike-slip fault system. Numerous structures visibly intersect, segment, dislocate and
distort each other in an intricate arrangement, that at least in part reflects the spherical geometry
of the Earth.
The dominant regional structures are evident on the satellite, aeromagnetic and digital
elevation images shown in Chapter 6 (Figs. 16 to 19 and 55a). They are also visible at outcrop
scale as faults, fractures and vein systems (Fig. 55b). The NE-trending faults are the most
frequently visible structures, although NW and NNE-trending faults are not uncommon. The

(b)

(a)

0

25

50

metres

Fig. 56a, b. Satellite image on the left and aerial photograph on the right showing the Net Ridge giant
quartz vein, which is a continuation of the right lateral offset Marian River Fault. In proximity to the fault
there are large quartz stockworks, an abundance of fractures and intense silica and potassic alteration.

- 134 -

NW-oriented faults are more easily identifiable in the Bea area on the satellite and magnetic
vertical gradient (MVG) aeromagnetic images (Figs. 21 and 23). There are also breaks in the
supracrustal rocks that orient in many other directions; however, there are no significant patterns
that can be established from these subordinate structures. They are relatively inconsequential
when compared to the large quantity of recognized primary structures and most are likely a
secondary consequence of primary tectonic features. An illustration of an interpretation of major
faults and their movements is shown in Figure 56.
The general trend of the observable major faults within the Mazenod Lake region is to the
NE (average orientation ~050°) (See rose diagrams that illustrate fault and/or lineament
orientations in Chapter 6, Figs. 19, 21 and 23). These are right-laterally displaced faults that are
subparallel to regionally significant transcurrent faults that occur throughout the GBMZ
(Hildebrand et al, 1986; Gandhi et al., 2001; Mumin et al., 2014; Hayward and Corriveau, 2014;
Ootes et al., 2015). Along with less recognizable left-lateral offset NW-trending faults (average
orientation ~340°) they form a conjugate system of steeply dipping faults (e.g. ~75° NW dip of
the Dianne Lake fault; Mumin et al., 2010). These fault sets are part of a regional conjugate fault
set that displaces and segments most of the GBMZ (Hoffman, 1980; Hildebrand et al., 1986;
Mitchell et al., 2010; Hayward and Corriveau, 2014). The NW-oriented faults often separate
stratigraphy along unconformities. A third significant set of right-lateral offset faults orients to
the NNE (average orientation ~020°). Analysis of satellite and aeromagnetic images, as well as
measurements taken directly in the field show that each of these major crustal breaks are oblique
strike-slip faults, with a near-vertical dip at surface, and horizontal displacements up to ~1.5 km.
A summary of the faults in the Mazenod Lake region and their estimated horizontal offset are
shown in Table 6 and Figure 57.

- 135 -

Fig. 57. Interpretation of major structures in the Mazenod Lake region. Digital elevation data courtesy
of the Ministry of Natural Resources.

- 136 -

Fig. 58. Estimated horizontal offset of major strike-slip faults within the Mazenod Lake region.
Measurements are estimated from a combination of structural field mapping, magnetic vertical gradient
data (MVG) offsets and satellite image observations. Digital elevation data courtesy of the Ministry of
Natural Resources.

- 137 -

TABLE 6. Dominant faults in the Mazenod Lake region and their estimated horizontal offset
Estimated Lateral Displacement1
400 m?
1100 m
150 m
1500 m
650 m
90 m
1000 m

Fault Name
Dianne Lake Fault
Marian River Fault
Upper Squirrel Lake Fault
Squirrel Lake Fault
Bea Fault
Kemaz Fault
Cross Lakes Fault
1

Estimates based on field mapping, aeromagnetic data, and satellite image measurements (Fig. 57).

A complete chronologic sequence of tectonic activity is difficult to determine for the
study area. Many of the faults of different orientations appear to offset each other. Despite the
difficulty, a general interpretation of age relationships can be substantiated from the analysis of
local structures and their spatial relationships. For instance, the hydrothermal alteration tends to
be focused along major structural corridors. This implies that the alteration hosting structures
were essentially coeval and/or pre-date the alteration and volcanic activity in the region.
Additional evidence for the similar timing relationship is demonstrated by structural breccias and
stockworks that are re-cemented with hydrothermal minerals. Further displacement of the
lithology and hydrothermal alteration that cannot itself be directly linked to volcanic or
hydrothermal activity is evidence that tectonic activity continued past periods of volcanism and
alteration that is now exposed at surface. Prior to emplacement of the volcanic assemblages
(Faber Group volcanism) the recognized system of major faults is likely to have already been in
place. If this hypothesis is true, the present tectonic framework could be a result of re-activation
of prevailing structures.
An indication of the component of dip-slip movement along the Kemaz oblique-slip fault
can be interpreted from the differences in lithology between bounding faults. At Dan Island, the
Kemaz fault separates a rhyodacite from an andesite (west and east sides respectively).
- 138 -

Assuming the stratigraphy has been correctly interpreted, the west flank of the Kemaz fault is
probably the down-dropped block. The eastern side of the Kemaz fault (up-thrown block) would
experience erosion to a deeper level, because the amount of exposure is greater. Eventually,
older lithology would be uncovered on the up-thrown side. This suggests that at Dan Island the
Kemaz fault has a component of reverse type oblique-slip faulting. Camier (2002) made a similar
interpretation for the Kemaz fault at the Sue-Dianne deposit.
The magnetic vertical gradient (MVG) data define three main areas that are characterized
by distinct and mostly unique magnetic lineament patterns (Fig. 58). These are tectonic blocks
segmented by major en echelon NE-oriented faults (strong magnetic discontinuities), that have a
similar dextral shear sense, but are disproportionally rotated and horizontally displaced. The
major tectonic blocks are identified here as the Mazenod, Squirrel and Bea tectonic blocks.
There is also a characteristic pattern of lineament orientations that distinctly separates the
volcanic belt and intense hydrothermal alteration from the surrounding intrusive rocks. The
plutonic rocks magnetic lineaments are predominantly oriented to the NE, essentially parallel to
the regional transcurrent faults. Within the volcanic belt, lineaments are mostly parallel to NWtrending structures and lithology. Unlike the NNE and NE oriented structures, there is no
apparent evidence on the satellite image, geophysical data or digital elevation data that indicates
NW-trending structures were active after volcanism. This suggests that the belt-parallel
structures and associated alteration were tied exclusively to the period of GBMZ volcanism.
Vertical axis clockwise rotation of the Mazenod tectonic block is revealed by the
disparate orientation of lithology at the flanks of the segmenting Marian River fault (Figs. 8 and
9). There is an approximately 130° dihedral angle (angle between two planes) between the
orientation of the Dianne Lake assemblage and the orientation of the Lou, Squirrel and Bea Lake

- 139 -

Fig. 59. Tectonic blocks are separated by transcurrent right lateral faults. Area within dashed lines
contains the volcanic belt. Magnetic vertical gradient (MVG) overlay of a satellite image of the
Mazenod Lake area.

- 140 -

assemblages, where the lithology is separated. The separation in lithology orientation was
unlikely to have developed during volcanism. More likely, post-volcanic disruptions caused the
shifting and rotation.
Left-stepping or bends along right-lateral offset transcurrent faults typically indicate
dextral transpression and an E-W shortening of the lithosphere along a fault. There is an obvious
example of this transpression along the Marian River fault, near Dan Island. South of the island a
left shifting kink in the right-lateral strike-slip fault links an oblique orientation of the fault that
continues through Net Ridge (Fig. 56). En echelon NE oriented faults correspondingly bend or
step at a similar longitude. The bend along the transcurrent faults is also readily apparent in
compilations of GBMZ geophysical data (Hayward et al., 2014).
The aeromagnetic data and geology also shows evidence of extensional characteristics
along NE-oriented structures. In the Bea area a significant magnetic-low lineament correlates
with a large diorite dyke, that fills in part of the Bea Fault. This large dyke, and several other
NE-oriented dykes and vein structures in the Bea area indicate a stretching direction between
~296° to 336° (assuming no significant rotation of the tectonic block), that has up to 150 m local
extension (Fig. 11). Total extension across the region is difficult to estimate, but must
accommodate fault, vein and fracture infill (e.g. Marian River and Dianne Lake fault giant quartz
vein systems) as well as various other intrusions such as the monzodiorite (c.f. Mumin et al.,
2010; 2014).
Major faults in the Mazenod Lake region have a distinctly recognizable association to
hydrothermal alteration, that is characteristic of the entire region. Throughout the study area, an
abundance of fractures, faults and structural breccias are cemented with hydrothermal minerals.
At Dan Island and Nod Hill, recognizable faults are in vicinity to the most intense hydrothermal

- 141 -

alteration. The hydrothermal alteration appears to be related to all the major and many secondary
faults, regardless of orientation. It should be commented that the relationship of NW-oriented
structures to alteration is more ambiguous than other primary structures. Typically, the major
structures are spatially affiliated with silica and/or potassic alteration, but regionally all the other
alteration types identified at surface have a spatial correlation with local structures. The NE and
NNE oriented structures are associated with the most intense hydrothermal alteration regionally,
including at Dan Island, Net Ridge, Nod Hill, along the Dianne Lake fault and close to the Bea
area (Mumin et al., 2010). These observations support evidence that the fault zones provided
permeable pathways for a greater concentration of hydrothermal fluids, which then fluxed
throughout the supracrustal rocks. The genetic association of structural breccias, faults and
hydrothermal alteration places a clear constraint on relative timing for hydrothermal alteration
and tectonic activity, which appear to have been essentially coeval. Notwithstanding the above,
major structures (e.g. NE-oriented faults) were clearly also active post-GBMZ volcanism.

Hydrothermal Alteration
The geochemical analysis documents the effects of widespread metasomatism throughout
the Mazenod Lake area. Nine distinct alteration types have been distinguished. They are
characterized by unique mineral assemblages, spatial zonation and unique geochemical
signatures. The alteration types include sodic, magnetite ± actinolite (MA), silication, potassic,
tourmaline, hematite, phyllic, propylitic and silica alteration.
Based on the detailed mapping, petrography and geochemical analysis performed for this
study, an interpretation of the local hydrothermal alteration zoning can be established. There is a
distinct pattern to the occurrence of alteration types and minerals, that repeats across the
Mazenod Lake region, irrespective of local geology. The spatial arrangement of alteration types
- 142 -

in general follows the sequence proposed by Richards and Mumin (2013b) (Fig. 4) (c.f. Hitzman
et al., 1992; Mumin et al., 2010; Corriveau et al., 2007). Higher temperature, neutral pH forming
hydrothermal alteration types are typically transitioned to lower temperature, more acidic pH
forming alteration types in the following order: sodic, magnetite ± actinolite (MA), potassic,
tourmaline, hematite, phyllic, propylitic and silica alteration. Exceptions exist, but in such
instances the out of place alteration may be related to separate overlapping hydrothermal cells or
multiple hydrothermal alteration events/pulses. Silication is not included in the zoning model
because it is not visible at surface, and is a consequence of primary rock composition rather than
zoning.
Mass balance testing has shown that diverse elemental exchanges accompany mineral
transformations during alteration in a series of distinct stages. For several of the alteration types,
there are surprisingly inconsistent element exchanges despite similar macroscopic hydrothermal
alteration. This indicates there may be unrecognized alteration in analyzed samples that is
invisible to the naked eye, which results in spurious gains and losses for certain elements in the
mass balance analysis. See Table 7 for a complete summary of typical element mobility patterns
associated with most of the alteration types found in the Mazenod Lake region.
Graphical analysis shown in binary plots (Figs. 30 and 31) and mass balance diagrams
(Figs. 34-42) indicate that Al, Ti, Zr and Hf are the most consistent and reliable immobile
elements in the suite of hydrothermally altered rocks from the Mazenod Lake area. Although
some alteration types show higher variations for gains and losses of Ti, Zr and Hf as compared to
Al, the mobility of these elements are more consistently similar than other typically immobile
element pairs. The most inconsistent immobile element exchanges take place during hematite

- 143 -

TABLE 7. Element mobility associated with most common Mazenod Lake region hydrothermal
alteration types1
Alteration
Type

Typical
Mineral
Assemblages

Immobile
Elements

Mobile Elements
Major Element Oxides
Trace Elements
Enriched
Depleted
Enriched Depleted

Albite ±
Magnetite

Al2O3,
TiO2, Ta,
Zr, Hf

Na2O

K2O, CaO,
MnO

Cr, Sn,
Bi, As

Rb, Zn,
Cs, Sr,
Mo

Magnetite ±
Actinolite

Al2O3,
TiO2, SiO2,
Zr, Hf, Tl,
Ta, HREEs

Na2O

K2O,
MgO,
MnO

Sn, As,
Cr, Ce

Cs, Zn,
Sr, Cd,
Be

K-feldspar ±
Biotite ±
Magnetite

Al2O3,
Fe2O3,
TiO2, SiO2,
Zr

K2O

Na2O,
CaO,
MgO,
MnO

Ba, Cr,
Rb, Te,
Th, U

Be,
HREEs,
Mo, Nb,
Nd, Ni,
Pb, Sc,
Sr, Zn

Tourmaline ±
Quartz

Al2O3,
TiO2, Zr, U,
Th, Se, Ta,
Tl

K2O,
SiO2,
Fe2O3

Na2O,
CaO,
MnO,
MgO

Ag, As,
Ba, Bi,
Co, Cr,
Hg, Mo,
Rb, Sb,
W

Be, Ce,
Cu, Pb,
Cs,
REEs, Sr,
Zn

Hematite

Hematite ±
Quartz

Al2O3,
TiO2, SiO2,
Th, Ta

Fe2O3,
MgO,
MnO,
K2O

Na2O,
CaO, P2O5

Hg, Cr,
Ga, Ge,
Sn, Te,
Tl, W

Cs, Pb,
Sr, Th,
Zn

Propylitic

Epidote ±
Chlorite ±
Carbonate ±
Quartz

Al2O3,
SiO2, Ag,
Ga, Hf, Nb,
Sc, Te, Th,
Tl, Y, Zr

MnO,
P2O5

MgO,
Na2O

Bi, REEs,
Cu, Sb,
Sr

Au, Ni,
Cs

Sodic2

MA

Potassic

Tourmaline

Ag, As,
Au, Bi,
Silicification Quartz
SiO2
Cu, Hg,
Eu, Sr
Mo, Nb,
Nd, Te
1
Several of the samples have been altered by an early-stage potassic alteration, which can impact the
major element oxides as spurious K2O enrichment and Na2O depletion for the alteration types listed in
this table.
2
Sodic alteration element exchanges based on the results of isocon mass balance tests of sodium
enriched samples shown in Figs. 35a, b.
Al2O3, Hf,
Ta, Th, U,
W, Zr,
REEs

CaO,
Na2O,
TiO2, P2O5

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alteration. This discrepancy indicates that in conditions which favor hematite alteration, the
typically immobile elements are more soluble in hydrothermal fluids.
The eight main types of alteration (visible at surface) that have been documented within
the Mazenod Lake region are summarized below in relative order from high-temperature
proximal types to the more distant, low-temperature alteration:
(a) Sodic Alteration
Analysis of Na-enriched rock samples show that concurrent to Na gains, K, Ca and Mn
are also leached from the rocks. This exchange of elements leads to the formation of secondary
albite. It is difficult to accurately identify the extent of sodic alteration, because it was not
identified in the field, although suspected. Despite the uncertainty of field data, analysis of
sodium enrichment residual alteration index (RAI) maps outlines sodic altered areas. These sodic
alteration zones extend north of Nod Hill and exist at the south end of the Bea area (Figs. 43 and
44). The Na may have been originally derived from a nearby cooling and crystallizing magma,
such as the monzodiorite south of Dan Island.
(b) Magnetite ± Actinolite (MA) Alteration
For MA-altered rocks, magnetite ± actinolite ± quartz is the preferentially formed
minerals. Mass balance testing shows MA-altered samples have mostly insignificant differences
in element exchanges from Na-enriched samples, other than a lack of Ca leaching. Since the
mass balance analysis has shown there is no observed significant hydrothermal enrichment of Fe
and Ca during magnetite ± actinolite alteration (Fig. 38), the wall rock must have had the
necessary abundance of Fe and Ca to crystallize the minerals. In spite of this observation, the CaFe enrichment RAI maps (which emphasize rocks enriched in Fe and Ca, Figs. 41 and 42) fairly
accurately correlate with regional MA alteration zones.
- 145 -

Investigations by other researchers of similar alteration often suggest there is
hydrothermal Ca-Fe enrichment during MA alteration (e.g. Montreuil et al., 2016). The MAaltered samples mass balance analyzed in this project did not show this enrichment apart from
sample 97124. The reason for the discrepancy in the geochemistry data may be related to sample
bias or misidentification of alteration in field notes. The data may also be skewed by the
presence of vein or breccia infill minerals in the samples.
(c) Potassic Alteration
Field observations and potassic RAI maps (Figs. 49 – 52) have shown how spatially
extensive potassic alteration is within the Mazenod Lake area. Mass balance analysis shows that
previously leached and/or magmatic derived K was deposited as K-feldspar ± biotite in potassic
altered samples. During this process, Na, Ca, Mg and Mn were leached from the altered rock.
Where this alteration is most intense, the host rock is converted to near monomineralic Kfeldspar. Dan Island is an obvious regional strong K-alteration anomaly. There also appears to be
increasingly intense potassic alteration in the central Bea area near the Bea Fault, which alludes
to a similar anomaly in the area.
(d) Tourmaline Alteration
Tourmaline alteration shows a similar element mobility pattern to potassic alteration.
This is due to mass balance tested samples that comprise superimposed secondary tourmaline on
previously potassic altered rocks. Since the tourmaline altered samples analyzed for this study
are known to contain spurious element exchanges, it is difficult to accurately remark on the
alteration process. Most research in similar settings suggest that the formation of tourmaline
alteration is linked to acidic, boron-bearing hydrothermal fluids reacting with country rock
(Henry and Dutrow, 1996). Temperature conditions are mostly not considered as a controlling
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factor for tourmaline alteration because of the wide temperature forming range. Like the other
main alteration types, secondary tourmaline is widespread, although the occurrence is sporadic
with local zones of intense alteration.
(e) Hematite Alteration
Hematite alteration occurs in two distinctly different forms, either as microscopic-sized
particles of hematite in K-feldspar or as veins and stockworks of hematite ± quartz. It is an
interesting observation that there is no evidence of significant Fe having been leached during any
of the other alterations, yet is significantly enriched during hematite alteration. The discrepancy
indicates that most of the Fe must have been transported by hydrothermal fluids from a source
other than previously leached wall rocks. The monzodiorite intrusion exposed near Dan Island is
one possible candidate as a magmatic source of iron.
(f) Phyllic Alteration
Phyllic alteration within the Mazenod hydrothermal system predominantly involves the
conversion of feldspar to sericite ± quartz. The pyrite that is typically linked with phyllic
alteration is characteristically minimal or often absent. This is possibly due to a lack of the ligand
sulphur, which is necessary to form pyrite. Richards and Mumin (2013a, b) discuss the apparent
S-poor content associated with similar magmatic hydrothermal IOCG systems, that may explain
the relative scarcity of sulphide minerals associated with this alteration. There is also field
evidence in localized areas of weathered out sulphides in the near-surface rocks, which partially
accounts for the relative scarcity of sulphides. Generally, phyllic alteration is considered to be
caused by a mild increase in acidity of hydrothermal fluids (Pirajno, 2009). This facilitates the
conversion of feldspars to white mica (sericite). Primary textures are typically preserved in this
type of alteration (c.f. Mumin et al., 2010). Although this alteration is widespread in the study
- 147 -

area, it is usually not obvious in outcrops. It is only through petrographic analysis that the
pervasive extent is revealed.
(g) Propylitic Alteration
Propylitic alteration is one of the more extensive alteration types within the Mazenod
hydrothermal system. This alteration produces secondary epidote ± chlorite ± carbonate ± quartz,
that occur together or less often independently. The propylitic alteration is usually not intense,
but there are areas of significant epidote alteration, including cemented hydrothermal breccias
southwest of Dan Island. Mass balance analysis shows that these altered rocks have generally
been enriched with Mn and P, whereas Mg and Na are leached. The enriched elements likely
originated from previously leached wall rocks and/or a magmatic derived source.
(h) Silicification
This is another common alteration in the Mazenod Lake region. Silicification
preferentially occurs along and in proximity to major faults, such as the Marian River and
Dianne Lake faults. During silicification, Si is enriched in the country rock, while Ca, Na, Ti and
P are depleted. Where space is available the alteration results in extensive quartz veins, stocks,
breccia bodies and/or replacement of local host rocks. The spatial relationship and superposition
of silica alteration over other alteration types implies the alteration is a late-stage retrograde
phase.

Residual Alteration Indices (RAIs)
The residual alteration index (RAI) maps are useful at illustrating distribution and
intensity of the various alteration types. By extension, the maps can also illustrate the progressive
migration of hydrothermal fluids through host rocks. The highest RAI values are generally

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located near significant permeable conduits that hydrothermal fluids used to penetrate the
surrounding country rock. Spatially separate areas that have distinct high RAI values are an
indication that there are several uniquely developed local hydrothermal cells within the Mazenod
Lake region. This essentially means there are several significant subsurface sources in the
Mazenod Lake region.
Areas containing high RAI values are characterized by an abundance of secondary
hydrothermal minerals. Around Mazenod Lake, the most apparent foci of alteration intensity
appear in several instances surrounding, along or adjacent to major faults, relatively close to the
monzodiorite intrusion. At and surrounding Mazenod Lake the field observations and RAI maps

Potassic Alteration
intensity in (%) of
maximum possible
100
90
80
70
60
50
40
30
20
10
0

Fig. 60. A close-up illustration of the potassic RAI I contours overlain on Dan Island. Arrows indicate an
estimation of the hydrothermal fluid migration directions from the permeable conduit- Kemaz Fault and
into the supracrustal rocks. In reality, the migration of fluids would involve a vertical component.

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coincide with a foci of alteration intensity at central Dan Island (Fig. 59) and in the northern
portion of Nod Hill (Figs. 49 and 50). In the Bea area, the foci of most intense alteration are
spatially difficult to delineate from the RAI maps because the lithogeochemical sampling does
not cover the entire area. Despite the lack of uniform sampling, local gradational changes in
hydrothermal alteration intensity can be used to interpret an approximate vector towards the most
intense alteration. For instance, in the center of the Bea area, potassic RAI values increase
continually to the southern edge of the sampled area (Figs. 44 and 46). The highest of these
values are adjacent to where the Bea Fault is interpreted to cross-cut the region. This increasing
trend of RAI values indicates that either the most intense potassic alteration is at the southern
limit of the sampled area or the intensity increases further south. A similar interpretation can be
made with the sodium enrichment index (Fig. 43). Sodium RAI values subtly increase towards
the southern edge of the mapped/sampled area, and could potentially continue to increase further
south outside of the study area.

Mineralization
As discussed in Chapter 5, there are several occurrences and varieties of mineralization
that have been identified across the Mazenod Lake region. Instances of Cu, Mo, Co, U, Fe and
LREE-bearing minerals have been observed, mostly in relatively small localized areas and
usually not in significant quantities. Chalcopyrite (CuFeS2) is the most common of these
minerals by far, but is generally irregularly dispersed. Local concentrations of chalcopyrite
typically are associated with alteration and/or structural disruptions and is often visible at surface
within oxidized (gossan) areas. Trace Cu-bearing minerals occur locally with most of the
recognized alteration types. Based on the spatial relationships of local mineral concentrations,

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hydrothermal alteration and faulting, their ages are considered to be broadly contemporaneous
with each other and Great Bear magmatism.

Implications for Exploration
A spatial comparison of the RAI values (Figs. 43 to 54) to concentrations of elements that
are commonly associated with IOCG-type deposits (indicator elements: Ag, As, Au, Bi, Co, Cu,
Hg, La, Mo, W, U; Figs. 62 to 72) show there is a relationship between hydrothermal alteration
intensity and indicator elements. For example, clusters of higher concentrations of indicator
elements tend to overlap with mid to higher potassic RAI contours (Figs. 45 and 47). Also,
clusters of low concentrations of indicator elements occur preferentially in most zones of intense
Ca-Fe enrichment (which correlates with intense MA alteration, Figs. 41 and 42). This
relationship is most obvious at the north end of Nod Hill. Not surprisingly, areas that are
comprised of higher RAI values that spatially correlate with higher concentrations of indicator
elements are also located along or adjacent to major strike-slip faults. The most significant
examples of areas containing these coincident features are at Dan Island adjacent to a splay of
the Kemaz Fault, Nod Hill along the Kemaz Fault and in the central Bea area along the Bea
Fault. Consequently, these coincident features are suggested as potential targets for additional
mineral exploration work.
An obvious global implication for this study is that the types of RAIs developed for the
Mazenod Lake hydrothermal system may be effective for delineating alteration types and
hydrothermal fluid migration in other IOCG hydrothermal systems. This is conditional on the
availability of an extensive geochemical database.

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Chapter IX: Conclusions
The broad goal of this investigation was to improve the general understanding of the
genesis of the large magmatic hydrothermal iron-oxide copper gold (MH-IOCG) system at
Mazenod Lake, NWT. Within this general objective, an emphasis of the investigation was placed
on analyzing the geology, structure and geochemistry. The following list describes several of the
more important conclusions made in this thesis:
1. 1:2000 scale geologic mapping at and surrounding Mazenod Lake revealed fourteen
unique relatively undeformed volcanic formations that make up the Faber Group volcanic
assemblages. These volcanic rocks are a series of sub-parallel pyroclastic ignimbrite
flows. Textural varieties range from ash, crystal and lapilli tuffs to pyroclastic breccias.
In-situ formed volcanic sediments unconformably separate many of the volcanic
assemblages, with the exception of the Squirrel Lake volcanic assemblage. A subvolcanic
monzodiorite intrusion that is a possible cause for alteration and mineralization exists in
the central area of Mazenod Lake, located between Nod Hill and Dan Island. Enclosing
the Faber Group volcanic and subvolcanic rocks is the genetically linked Marian River
granitoid batholith to the east and Sarah Lake monzogranite to the west. Overlying the
aforementioned geology in the western third of the area are Paleozoic sedimentary strata.
2. Geochemical analysis of the Mazenod Lake area examines a near-horizontal slice through
a volcanic system, controlled by the current depth of erosion and outcrop exposure. The
spatially controlled geochemical data reveal patterns linked to unique characteristics of
lithology and hydrothermal alteration.
3. Chemical discrimination of the Mazenod Lake area lithology has shown that the volcanic
rocks are compositionally mostly andesite, but also include basaltic andesite, dacite and
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rhyodacite. Chemical tectonomagmatic discrimination of the least-altered rocks shows
these rocks have a calc-alkaline character. Granite discrimination diagrams support an
interpretation that the least-altered granitoid rocks formed in a syn-collisional and
volcanic arc tectonic setting.
4. The Mazenod Lake region structural framework is characterized by mostly brittle strikeslip tectonics. There are several sets of en echelon oblique strike-slip faults that intersect,
segment and displace the local lithology. Faults have three main directional trends that
orient mostly N50°E, N30°W and N20°E. The NE and NW oriented faults are interpreted
to be a conjugate pair, part of the regional GBMZ faulting. The NNE faults may have
been a result of transferring stress between differentially displaced NE oriented en
echelon faults.
5. Density analysis of lineaments and their intersections spatially evaluates areas of greatest
strain. Zones of concentrated deformation include the Sue-Dianne deposit, Dan Island,
the central Bea area and an area NE of the Sue-Dianne deposit within the Marian River
batholith. The areas which have significantly dense quantities of lineaments and
lineament intersections tend to occur in close proximity to intersections of major faults,
and in at least three out of the four anomalous zones, areas of minor concentrations of
mineralization. However, the lineament density analysis is strongly biased towards areas
with a high density of outcrop exposure.
6. Three main tectonic blocks have been recognized in the Mazenod Lake region. They are
characterized by similar patterns of lineaments that were derived from remotely sensed
images. Defining the tectonic blocks emphasizes the differential deformation the region
has experienced. While each tectonic block has a dextral shear sense, the amount of

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horizontal shift and rotation is unique for every block. In the northern part of the region,
the Mazenod tectonic block appears to have been rotated about a vertical axis,
significantly more than the southern Squirrel and Bea tectonic blocks.
7. Hydrothermal alteration is pervasive within the Mazenod Lake region, with no truly
completely unaltered rocks visible at surface. Prevailing alteration includes the proximal
high-temperature alteration types, sodic, MA (magnetite ± actinolite) to the more distal
intermediate and lower-temperature alteration types potassic (K-feldspar ± biotite),
tourmaline, hematite, phyllic (quartz, sericite ± pyrite), propylitic (epidote ± chlorite ±
carbonate ± sericite ± quartz), and silicification. Silication-type in the form of skarn
metasomatism (clinopyroxene-garnet-magnetite) has also been identified, although
because the alteration was not recognized at surface it was not included in the
geochemical analysis. These various alteration types occur locally as replacements,
stockworks, veins and hydrothermal breccias. In general, paragenesis of the alteration
minerals follows the zoning model of proximal to distal alteration assemblages (Richards
and Mumin, 2013b).
8. The Mazenod hydrothermal system is believed to be a magmatic-hydrothermal type
IOCG system that was driven by the intrusion of a monzodiorite pluton(s) into mostly
andesitic volcanic rocks. This system is characterized by pervasive alteration,
predominantly potassic, but includes all the common types of an IOCG system. There are
several local hydrothermal cells that exist as part of the regional Mazenod hydrothermal
system. Each cell visibly has gradational changes in alteration intensity. They also have
overlapping alteration halos which locally obfuscate the established zoning model.

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Unique hydrothermal cells are revealed on the RAI maps, which demonstrates their areal
extent and systematic gradational change of alteration intensity.
9. Evaluation of elemental exchanges involved in the hydrothermal alteration process shows
there is a pattern to the alteration processes. Early and hotter reactions involve the
enrichment of country rock with Na and a simultaneous leaching of K, Mg, Ca and Mn
leading to the formation of hydrothermal albite. As the fluid is convected throughout the
hydrothermal system, changing physico-chemical conditions and hydrothermal fluid
chemistry resulted in varying element substitutions and crystallization of different
minerals. During magnetite ± actinolite alteration, Ca was no longer leached. With
potassic alteration, K is enriched, while Na, Mg, Mn and Ca are depleted. Hematite
alteration is associated with an Fe enrichment. The Fe likely originated from a source
other than previously leached wall rocks, because there is little evidence of any alteration
causing significant Fe leaching with the exception of intense albitization not observed in
surface rocks at Mazenod, but known to occur elsewhere in the GBMZ (Mumin et al.,
2010). In propylitic alteration, Mn and P are enriched in country rock, while Mg and Na
are leached. Silicification then involved an enrichment of Si in country rock and leaching
of Ca, Na, Ti and P.
10. Several residual alteration indices (RAIs) have been developed and interpolated that have
potential exploration applications. These RAIs have been shown as useful for delineating
various hydrothermal alteration types, showing possible migratory paths for the
hydrothermal fluids and locating hydrothermal centres.
11. Analysis of the geology, structure and geochemistry of the Mazenod Lake region reveals
hydrothermal centres. Dan Island, Nod Hill and the central Bea area are the most evident

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centers of hydrothermal activity. These locations all contain intense alteration, are crosscut by regionally disruptive faults, have evidence of mineralization, and contain greater
concentrations of indicator elements than the surrounding areas.
12. Exploration of the Mazenod Lake region is still in the preliminary stages and economic
mineralization remains to be discovered. While there is additional ground work that could
be completed to reveal unexplored geology, expand upon the geochemical or geophysical
database, in order to successfully diagnose potential economic mineralization, a full
exploration drilling program is recommended. On the basis of this thesis, hydrothermal
centers located at Dan Island, Nod Hill and in the central Bea area are considered primary
targets for additional exploration activity.

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Williams, P.J., 2010, Classifying IOCG deposits: Exploring for iron oxide copper–gold deposits:
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- 174 -

Appendix I: Petrographic Analysis

- 175 -

Thin sections were cut from 6 samples that represent several rock types, alteration types
and uniquely mineralized samples. Sample 98197 was also analyzed using the scanning electron
microprobe (SEM). Each sample was photographed and cut into thin sections using Brandon
University’s lapidary facilities. Several of these sections were polished for reflected light
microscopy analysis. Samples were individually examined in transmitted and/or reflected light to
determine petrography of each sample. Analysis was performed using A Nikon Eclipse E600
POL microscope in the Laboratory for Applied Research in Resource Geology at Brandon
University. Texturally interesting features or mineral anomalies were photographed using an
attached Canon Rebel T4i EOS 650D. Petrography, mineralogy and descriptions are summarized
in Table 10.
Sample 98197 was carbon coated to a thickness of 15 nm and analyzed using a JEOL
JSM-639OLV/GS SEM, equipped with an Oxford Instruments INCA x0act Energy Dispersive
Spectrometer (EDS) X-ray detector. Operating conditions include a 20kV accelerating voltage
for 30-s count times using Inca Energy software and the XPP correction scheme developed by
Pouchou and Pichoir (1990). Semi-quantitative analysis was collected (normalized to 100%) and
standardized to the Oxford INCA default settings. Microprobe images and associated tables
follow the thin section petrographic report. The SEM analysis was performed for the purposes of
potentially identifying minerals associated with anomalous geochemically reported tungsten
content.

- 176 -

Sample
Analysis1
Rock Type2
Thin Section Figures 61a-h
Hand Sample Description

Primary Minerals

TABLE 8. Hand sample and thin section analysis of selected rocks.
96224
97078
Reflected & Transmitted Light
Transmitted Light
Andesite (A3)
Monzodiorite (MD)
(a), (b)
(c)
Slightly gossaneous and stained
Relatively unaltered in
with malachite andesite
appearance monzodiorite
ignimbrite. Trace sulphides
subvolcanic intrusion.
visible, most likely chalcopyrite
Contains ~30%
and lesser pyrite. Fragmentals
inequigranular plagioclase
range from 1 - 5 mm, with
phenocrysts ~2% of which
quartz making up the larger
are poikilitic (black <0.01
proportions. Veins of magnetite
mm inclusions?).
present making up ~2-3%. ~2%
Sausseritization of
has bright red plagioclase
plagioclase. Contains ~ 5%
phenocrysts, from hematite in
biotite phenocrysts, trace
crystal structure
K-feldspar

98021
Transmitted Light
Rhyodacite (R3)
(d)
Somewhat bleached
appearance containing ~510% very sausseritized
subhedral plagioclase
phenocrysts and 2-3%
quartz phenocrysts, both
~1-2 mm diameter. Also
contains ~1% mafic
minerals, probably biotite
and ~1% of an unknown
bleached white tabular
trachytic mineral

Plagioclase

~15% - Phenocrysts ~30% has
been replaced with sericite.
Often fractured and commonly
has resorption textures. About
half appear fragmental (shardlike) and the rest are euhedral
phenocrysts

~25% - Inequigranular
phenocrysts mostly
euhedral with common
resorption and crystal
zoning textures

Only relict shapes.
Completely replaced with
very fine-grained crosshatched pattern of sericite

Quartz

~5% - Commonly has resorption
textures with embayments

~2-3% - 1% of phenocrysts
up to 1 mm and is seriate
within groundmass.
Commonly has resorption
textures

~5-7% quartz phenocrysts
up to 2-3 mm. Most are
fractured with fractures
filled with sericite

- 177 -

Characterizing &
Accessory Minerals

Groundmass

~45% - Sericitzed, appears to be
mostly composed of plagioclase

~70% - Appears to be
predominantly (but
unknown %) plagioclase
with lesser quartz

Appears to be
predominantly (but
unknown %) plagioclase
with lesser quartz

Biotite

Mostly relict minerals replaced
by chlorite and calcite

2-3% - Phenocrysts ~1-2
mm on average. Oikocrysts
with ~1% magnetite within
the biotite. Associated with
a chlorite replacement

Predominantly replaced
by chlorite

Titanite

-

Trace - Associated with
biotite phenocrysts

-

Trace - Associated with chlorite

-

-

Titanite

-

-

-

Calcite

~1% - Associated with chlorite
and epidote as veins and
pseudomorphic replacement

-

-

Chlorite

~3% - Chlorite veins and
pseudomorphic replacement of
biotite. Associated with trace
quartz and greater calcite and
epidote

~1% - Hydrothermal
replacement of biotite
phenocrysts

~2% - Hydrothermal
replacement of biotite
phenocrysts

Hydrothermal Minerals Epidote

- 178 -

Apatite

Trace - Chadacrysts within
plagioclase

-

-

Sericite

~5% - Replacement of the
feldspar phenocrysts and
groundmass

Approximately 10% of the
plagioclase phenocrysts
have been replaced with a
very fine-grained sericitic
alteration product. The
sericite does not affect the
groundmass

~70% - Veins and
pseudomorphic
replacement of feldspars.
All of the feldspars are
completely converted to
sericite, only relict shapes

Quartz

Trace - <1 mm diameter veins

-

Magnetite

~2% - Chadacrysts within
chlorite. Ilmenite exsolution
within the magnetite

Chadacrysts within biotite
and chlorite.

Trace - associated with
sericitic replacement of
feldspars and sericite
veins
Chadacrysts within biotite
and chlorite.

Hematite

Trace - Associated with
magnetite

-

-

Sulphides

~1% - Pyrite and chalcopyrite.
Probably multiple crystallization
phases but pyrite definitely
encloses magnetite indicating an
earlier crystallization phase of
magnetite. Like the magnetite,
forms within veins of chlorite

-

-

- 179 -

Sample
Analysis*
Rock Type**
Thin Section Figures 61a-h
Hand Sample Description

98089
Transmitted Light
Dacite (D1)
(e)
Relatively unaltered in
appearance dacite
ignimbrite. Strongly
magnetic. Containing
approximately 20%, 14 mm subhedral euhedral plagioclase
phenocrysts in a light
grey slightly siliceous
looking matrix

98157
Reflected & Transmitted Light
Basaltic Andesite (BA1)
(f)
Rock has a high specific gravity.
Contains very metallic red looking
hematite (almost looks like sphalerite).
Contains veins of mm-scale epidote
surrounded by red staining (probably
more hematite). Weathered surface has
pink staining reminiscent of cobalt
bloom. Few k-feldspar veins, not as
many and smaller than the epidote
veins

98197
Transmitted Light
Andesite (A3)
(g), (h)
Malachite stained on
weathered surface,
fresh surface has trace
barely visible
sulphides
(chalcopyrite?).
Reddish hue to rock
and veins of black
material that pervades
it

Primary Minerals

~20% - Mostly
euhedral and
predominantly (~80%)
serictized. ~15%
replaced with epidote
and ~1% with calcite
-

~20% - Cut sample is mostly vein
material, but groundmass appears to be
predominantly plagioclase that is often
perthitic.

Phenocrysts
completely replaced
with very fine-grained
sericite

-

-

Plagioclase

Quartz

Groundmass Appears to be
composed of micron
and smaller sized
plagioclase

Appears to be plagioclase

- 180 -

Appears to be
plagioclase

Characterizing &
Accessory Minerals

Biotite

Trace - Mostly relict
biotite, replaced with
epidote, chlorite and/or
magnetite

-

-

Titanite

-

-

-

~2% - Predominantly
replacing groundmass
and on the periphery of
plagioclase
phenocrysts. Micronscale veins
disseminated
throughout. ~15%
associated with chlorite
veins
Trace - Epidote veins
and replacement
commonly form around
titanite crystals

~70% - Thin section is predominantly
from an epidote vein ~1.2 cm in
diameter. Mostly very fine-grained but
a few >1 mm crystals near a quartz
vein

Trace - Associated
with chlorite

-

Trace - Associated
with chlorite

Trace - Veins within
plagioclase
phenocrysts. Earlier
phase alteration than
the sericite replacement
(sericite forms around
calcite veins)

-

Hydrothermal Minerals Epidote

Titanite

Calcite

- 181 -

-

Chlorite

~2% - Occurs
predominantly in
groundmass as ~0.001
mm veinlets associated
with magnetite and
quartz

Apatite

-

-

Sericite

~15% - Has replaced
~60% of the
plagioclase
phenocrysts. Trace
association with
carbonate.
Trace - Hydrothermal
quartz associated with
micron-scale actinolite
veins

Trace - in phenocrysts and groundmass

~50% - Complete
replacement of
plagioclase
phenocrysts

Vein of quartz is earlier alteration
product than the epidote. Chilled
margin surrounding the quartz vein

~5% - <0.01 - 1 mm
veins of quartz. It is
offset and cross-cut
by larger epidote
veins
Trace - Disseminated
in groundmass

Quartz

Magnetite

Trace - Associated with epidote

~10% - Disseminated
Trace - few euhedral phenocrysts
and poikilitic
within a quartz vein - earlier phase of
throughout groundmass alteration than quartz vein?
euhedral magnetite
from < micron to 0.1
mm. Concentrated
magnetite crystals are
associated with chlorite
veinlets

- 182 -

~20% - Veins of
chlorite that cross-cut
and follow preexisting quartz veins.
In local zones
replacing feldspars
and sericite
-

Hematite

Sulphides

1
2

-

~5% of the plagioclase phenocrysts
have a brownish-siderite appearance.
Likely due to hematite being within the
crystal structure of the plagioclase.
Veins of hematite cross-cut the epidote

~1% Within crystal
structure of feldspars
and few <0.01 mm
euhedral crystals

-

?

Trace unknown
sulphide (possibly
chalcopyrite)

Sulphides and other typical opaque minerals only capable of being identified in reflected light microscopy.
See North Mazenod map for comparable rock type classifications.

- 183 -

- 184 -

- 185 -

- 186 -

- 187 -

9.

- 188 -

- 189 -

- 190 -

- 191 -

- 192 -

- 193 -

Fig 62a-n. Backscattered electron microprobe images of selected sites in sample 98197. See
Table 11 for spectrum assay results.

- 194 -

Appendix II: Formulas

- 195 -

Formula derived from mass balance analysis and isocon diagrams (Grant, 1986):

Equation of the isocon line:
𝐶𝐴 = (

𝑚𝑜 𝑂
)𝐶
𝑚𝐴

Percent elemental change:
𝐶𝑖𝐴
𝐶𝑖𝑂
𝛥𝐶𝑖 % =
− 1 ∗ 100%
𝑚𝐴
𝑚𝑂 ]
{[
}

Change in mass:
𝑚𝑂
𝛥𝑀% = [( 𝐴 ) − 1] ∗ 100%
𝑚

Where: CA= Concentration of component altered sample
CO= Concentration of component of least-altered sample
mA = Concentration of immobile element in the altered sample (usually Al2O3)
mO= Concentration of immobile element in the least-altered sample (usually Al2O3)
Ci= Concentration of component i
CiA= Concentration of component i in altered rock
CiO= Concentration of component i in least-altered rock

- 196 -

Appendix III: Sample Descriptions

- 197 -

TABLE 10. Sample descriptions amalgamated from sample booklet data, field notes and later observations for those samples undergone mass
balance analysis in this study.
Sample ID
96217

Easting
502880

Northing
7065083

Host Rock
Andesite

Alteration Classification
Mineralized

Description
Fractured and mildly potassic altered crystal tuff
with actinolite, magnetite and chlorite? Contains
vein with pyrite chalcopyrite and arsinides?
Erythrite and malachite present

96222

502875

7065066

Andesite

Mineralized

Potassic altered with minor weathered sulphides
along fracture

96227

502765

7065118

Andesite

Hematite + Potassic

Potassium altered fracture zone, 5% specular
hematite. Vuggy weathered

96232

502540

7065013

Rhyodacite

Potassic

Felsite with disseminated sulphides, slightly
magnetic

96233

502577

7065232

Rhyodacite

Tourmaline

Strongly potassic altered rock with tourmaline
crackle breccia and phyllic overprint along with
minor disseminated pyrite

96238

502465

7064891

Andesite

Hematite

Potassic altered crackle breccia rock cemented
with hematite

96239

502542

7064976

Rhyodacite

Potassic

Felsite with hematite veins and slightly
magnetic. Sulphide boxwork structures/pits

96240

502594

7064962

Andesite

Potassic

Brecciated strongly potassic altered rock

96259

502321

7065561

Andesite

Least Altered

- 198 -

Porphyritic andesite feldspar crystal tuff. 15-20%
1-3 mm plagioclase phenocrysts, 2-3% up to 1
cm plagioclase phenocrysts in a dark grey
matrix. Trace pyroxene and carbonate along a
fracture

96260

502129

7065560

Andesite

Carbonate

Minor carbonate veining in a weakly potassic
altered lapilli tuff. Minor weathered out
sulphides along fracturing

96309

504174

7065162

Andesite

Least Altered

Least altered feldspar-quartz crystal tuff

96386

504696

7065636

Basaltic Andesite

Epidote

Epidote altered associated with up to 1%
euhedral pyrite. Hosted in a crystal tuff

96392

505694

7056379

Dacite

Silicification + Potassic +
Magnetite

Strongly potassic altered and silicified. Also
contains magnetite veins up to 3 cm thick

96397

505495

7056659

Dacite

Propylitic

Brecciated and bedded ash tuff cemented with
epidote that is associated with a minor amount
of sulphides

96405

501787

7066243

Rhyodacite

Hematite

Fine-grained with pervasive hematite staining
and veining with a structurally fractured zone

96423

501367

7065050

Andesite

Least Altered

Crystal tuff with a very fine-grained dark matrix.
Contains ~15% 0.5-3 mm feldspar phenocrysts.
Trace alteration minerals of K-feldspar, epidote
and magnetite noted in fractures

96427

500824

7065429

Dacite

Silicification

Strong alteration, Pervasive k-feldspar and
quartz, moderate to strong potassic alteration,
Lapilli appears silicified (dark v.f.g colour). Fine
epidote veins and clots, but not nearly as
abundant as previously, rock has pervasive weak
to moderate magnetism

96443

501453

7064395

Monzogranite

Least Altered

Coarse-grained granitoid

- 199 -

96444

501191

7064237

Monzogranite

Least Altered

96479

502581

7065216

Rhyodacite

Tourmaline + Silica +
Potassic

Crystal tuff altered to felsite. Stockwork of fine
mm-scale tourmaline-quartz veins

97005

501749

7062411

Andesite

MA

Crystal tuff containing actinolite crystals 2-5mm,
pink-red-purple matrix. Med-fine-grained

97030

501021

7063174

Rhyodacite

Silicification

Sample acquired from near uranium exploration
trench. Quartz breccia hosted within a crystal
tuff

97041

501667

7063150

Rhyodacite

Potassic

Strongly potassic altered and quartz-rich in
phenocrysts. Trace magnetite. Fine cherty ash
matrix. 2-3% mafic grains.

97055

501407

7063494

Monzogranite

Least Altered

Fine-grained granitoid. 1-2 mm crystals of quartz
and feldspar. 25-30% quartz, 20% plagioclase, 34% biotite and 45-50% K-feldspar. Sucrosic
texture with a pink fresh surface

97057

501224

7063776

Rhyodacite

Least Altered

Phenocrysts of feldspar, quartz and biotite,
possibly a lapilli tuff. Aphanitic light grey matrix
material. Contains minor amount of amphiboles
and biotite

97063

502143

7063695

Rhyodacite

Hematite + Quartz

Crystal Tuff hosting massive quartz-hematite
rich vein. Sample is mostly hematite

97078

502387

7064262

Monzodiorite

Least Altered

Massive dark grey, with crystalline grains of
biotite and feldspar up to 4 mm

97094

502864

7062516

Rhyodacite

Mineralized

Vuggy quartz vein + actinolite + pyrite +
chalcopyrite in a crystal tuff

- 200 -

Medium-grained granitoid

97095

502875

7062501

Rhyodacite

MA

97099

502944

7062571

Andesite

Mineralized

Moderate to strongly potassic altered with 1
mm phenocrysts of pink-red-grey K-feldspars
and <1% mafic minerals. Fine to medium
grained, weakly magnetic and may contains
some hematite

97123

502192

7061400

Rhyodacite

Potassic

Strongly potassic altered tuff with traces of
pyrite and magnetite. Almost a felsite.
Sugary/cherty texture.

97124

502226

7061496

Andesite

MA

Magnetite breccia with associated epidote and
disseminated sulphides

97129

502278

7061524

Rhyodacite

MA

Crystal tuff with hydrothermal magnetite and
sulphides from the top of Nod Hill

97138

502315

7061428

Rhyodacite

Mineralized

Magnetite crackle breccia with minor pyrite,
chalcopyrite and malachite

97143

502300

7061713

Rhyodacite

Mineralized

Crystal tuff with magnetite and sulphides in
veins. Moderate potassic alteration

- 201 -

Structural breccia containing actinolite and
magnetite which are associated with trace
chalcopyrite and 1% or greater pyrite.
Silicification occurring at the outer edge of the
actinolite veins. Contains several <1 mm veins of
magnetite that are cross-cut by the actinolite
veins

97227

505382

7056684

Dacite

Tourmaline

Rock that has 'red rock' alteration of hematite
and k-feldspar. Stockwork veins > 1 cm wide of
tourmaline pervade this rock. Central in some of
the veins is quartz veins

97228

505396

7056604

Dacite

Tourmaline

Tourmaline veined and brecciated. Sulphides
(pyrite) associated with the tourmaline veins.
<0.1 mm scale veins of K-feldspar. Host rock is
bright red, from suspected hematite and kfeldspar alteration

97249

505789

7055914

Andesite

Mineralized

Crystal tuff containing chalcopyrite associated
with magnetite

97254

505483

7055703

Dacite

Hematite + Quartz

Hematite quartz cemented breccia containing
trace sulphides. Rock is heavily weathered.

97258

505509

7055692

Andesite

Mineralized, Tourmaline

Tourmaline breccia with minor hematite and
sulphides

97266

505355

7055298

Andesite

Tourmaline

Tourmaline quartz breccia containing trace
pyrite

98024

503196

7064111

Volcanic
Sediments

Least Altered

Thin bedded sediment. No visible alteration

98032

502473

7063661

Rhyodacite

Silicification

Vuggy quartz vein that has association with
hematite

98089

503944

7063923

Dacite

Least Altered

Lapilli tuff. Outcrop surrounding least altered
piece contained minor epidote alteration

- 202 -

98098

503684

7064094

Dacite

Carbonate

Ash tuff with minor carbonate

98151

499921

7064864

Monzogranite

Least Altered

Whitish-pink, no visible alteration. Rock contains
~60% quartz crystals and 20% K-feldspar and
plagioclase makes up the reset. ~1% mafic
minerals, biotite?

98156

499638

7064361

Basaltic Andesite

Least Altered

Greyish ash tuff, no visible alteration effect. Up
to 5% 1-3 mm feldspars

98172

499830

706520

Andesite

MA

Strongly potassic altered rock with abundant
clots of actinolite-magnetite

98185

500195

7065530

Andesite

Epidote

Crystal tuff, strong epidote, trace - pyrite,
chalcopyrite and malachite

98191

500419

7065247

Basaltic Andesite

Epidote

Crystal tuff containing actinolite, epidote
breccia. Weakly potassic altered

98207

498424

7064858

Andesite

Silicification

Silicified crystal tuff. Contains ~3% pyrite

98244

505529

7054416

Andesite

Carbonate

Crystal tuff with epidote and magnetite veining
plus trace sulphide. Outcrop was brecciated with
dolomite or a ferrocarbonate

98271

505710

7067564

Basaltic Andesite

Epidote

Ash tuff containing an epidote breccia
associated with lesser actinolite. Almost an
epidotite

- 203 -

Appendix IV: Common Indicator Element Concentrations

- 204 -

Fig. 63. Distribution of silver concentrations in the Mazenod Lake region.

- 205 -

Fig. 64. Distribution of arsenic concentrations in the Mazenod Lake region.

- 206 -

Fig. 65. Distribution of gold concentrations in the Mazenod Lake region.

- 207 -

Fig. 66. Distribution of bismuth concentrations in the Mazenod Lake region.

- 208 -

Fig. 67. Distribution of cobalt concentrations in the Mazenod Lake region.

- 209 -

Fig. 68. Distribution of copper concentrations in the Mazenod Lake region.

- 210 -

Fig. 69. Distribution of mercury concentrations in the Mazenod Lake region.

- 211 -

Fig. 70. Distribution of lanthanum concentrations in the Mazenod Lake region.

- 212 -

Fig. 71. Distribution of molybdenum concentrations in the Mazenod Lake region.

- 213 -

Fig. 72. Distribution of tungsten concentrations in the Mazenod Lake region.

- 214 -

Fig. 73. Distribution of uranium concentrations in the Mazenod Lake region.

- 215 -

Appendix V: Mass Balance Data

- 216 -

TABLE 11. Results of Mass-Balance Calculations
Average Least Altered Andesite

96217

96222

96227

Altered

% Gain or Loss

Altered

% Gain or Loss

Altered

Elements

Least altered Ci

Ci

ΔCi%

Ci

ΔCi%

Ci

ΔCi%

Au (ppb)

2.67

77

3135.24%

147

5990.59%

29

1852.85%

Ag (ppm)

0.05

0.4

797.46%

0.05

10.63%

0.2

619.19%

As

8.17

698

9484.31%

1430

19262.76%

219

4719.52%

Ba

767.67

1210

76.82%

1570

126.24%

645

51.07%

Be

2

1.6

-10.25%

1.7

-5.97%

1.5

34.85%

Bi

0.32

172

60198.42%

113

38964.45%

664

372978.44%

Cd

0.15

0.2

49.58%

0.2

47.50%

0.1

19.86%

Ce

70.67

48

-23.80%

114

78.45%

33

-16.04%

Co

14.53

395

2949.71%

480

3554.51%

143

1669.51%

Cr

90

135

68.27%

122

49.96%

58

15.87%

Cs

3.7

1.8

-45.42%

2.6

-22.26%

0.6

-70.84%

Cu

31.43

229

717.37%

216

660.26%

329

1782.06%

Dy

3.61

3.82

18.71%

2.68

-17.87%

9.59

377.63%

Er

1.94

2.64

52.66%

1.5

-14.47%

8.17

657.19%

Eu

1.23

1.32

20.39%

1.95

75.38%

1.34

95.88%

Ga

17.23

16

4.17%

19.4

24.56%

18.4

92.01%

Gd

4.21

3.33

-11.27%

4.58

20.35%

5.14

119.51%

Ge

1.37

1.1

-9.93%

1.3

4.97%

1.3

70.61%

Hf

4.67

5.2

24.91%

4.6

8.97%

2.4

-7.60%

Hg

0.05

0.4

797.46%

2

4325.00%

0.1

259.59%

Ho

0.87

1.04

34.10%

0.59

-24.98%

3.21

563.39%

La

38.67

24

-30.38%

61

74.51%

19

-11.66%

Lu

0.3

0.8

199.15%

0.3

10.63%

1.6

858.92%

Mo

1.7

0.8

-47.21%

7.7

401.07%

1

5.76%

Nb

7

7

12.18%

7

10.63%

3

-22.94%

Nd

27.8

18.8

-24.14%

41.5

65.14%

13.8

-10.75%

Ni

14.67

23

75.88%

35

163.93%

23

181.89%

Pb

12.46

8.85

-20.32%

12

6.54%

4.04

-41.70%

Pr

8.39

5.37

-28.20%

12.3

62.18%

3.94

-15.57%

Rb

178

279

75.84%

346

115.04%

123

24.24%

Sb

3.67

6

83.41%

6

80.86%

11

438.90%

Sc

12.33

12

9.18%

12

7.66%

27

293.72%

Se

1.17

0.5

-52.06%

1

-5.45%

0.5

-23.16%

Sm

4.84

3.92

-9.14%

6.41

46.51%

3.59

33.36%

Sn

3.72

11.1

234.74%

4.1

21.93%

9.3

349.49%

Sr

184.33

61

-62.88%

51

-69.39%

24

-76.59%

Ta

1.42

1.09

-13.89%

1.11

-13.53%

0.61

-22.76%

Tb

0.65

0.6

3.55%

0.59

0.41%

1.18

226.40%

Te

0.05

0.05

12.18%

0.5

1006.25%

0.2

619.19%

Th

17.97

18.1

12.99%

16.4

0.96%

7.3

-26.96%

Tl

0.01

0.005

-43.91%

0.005

-44.69%

0.005

-10.10%

Tm

0.35

0.58

85.90%

0.26

-17.82%

1.58

711.65%

U

6.02

6.64

23.74%

5.82

6.95%

3.35

0.05%

V

88.33

89

13.03%

82

2.70%

83

68.95%

0

% Gain or Loss

W

11

48

389.53%

216

2072.27%

12

96.14%

Y

21.53

26.3

37.04%

14

-28.07%

93

676.64%

Yb

2.07

4.3

133.04%

1.85

-1.13%

9.97

765.98%

Zn

66.33

15

-74.63%

36

-39.96%

36

-2.42%

Zr

161.33

161

11.95%

143

-1.94%

74

-17.53%

Al 2O3 (wt.%)

15.93

14.2

0.00%

14.4

0.00%

8.86

0.00%

CaO

3.74

1.26

-62.21%

0.54

-84.03%

7.03

237.96%

Fe2O3

5.85

7.73

48.24%

10.5

98.56%

25.6

686.80%

MgO

2.13

2

5.34%

2.07

7.51%

5.87

395.50%

MnO

0.14

0.07

-43.91%

0.07

-44.69%

0.28

259.59%

P2O5

0.11

0.08

-18.41%

0.09

-9.49%

0.005

-91.83%

K2O

4.21

9.61

156.08%

9.54

150.68%

4.64

98.16%

Na2O

3.13

1.27

-54.48%

1.43

-49.46%

0.09

-94.83%

TiO2

0.61

0.54

-0.69%

0.55

-0.26%

0.28

-17.47%

SiO2

61.67

60.3

9.69%

57.1

2.43%

34.6

0.88%

LOI

2.67

2.8

17.65%

3.7

53.30%

12.7

755.21%

Mass change

12.18%

10.63%

- 217 -

79.80%

Average Least Altered Andesite
0

Altered

96238
% Gain or Loss

Altered

96240
% Gain or Loss

Altered

96260
% Gain or Loss

Elements

Least altered Ci

Ci

ΔCi%

Ci

ΔCi%

Ci

ΔCi%

Au (ppb)

2.67

13

450.08%

6

132.45%

1

-63.84%

Ag (ppm)

0.05

0.05

12.98%

0.9

1761.95%

0.05

-3.45%

As

8.17

12.6

74.24%

19.4

145.63%

6.1

-27.92%

Ba

767.67

2720

300.30%

3000

304.24%

1100

38.34%

Be

2

1.1

-37.86%

1.1

-43.11%

1.6

-22.76%

Bi

0.32

2.9

923.87%

0.6

93.95%

0.05

-84.91%

Cd

0.15

0.3

125.96%

0.2

37.92%

0.2

28.73%

Ce

70.67

194

210.14%

40

-41.45%

47

-35.79%

Co

14.53

4.6

-64.23%

7.7

-45.18%

15.8

4.98%

Cr

90

123

54.40%

164

88.49%

86

-7.75%

Cs

3.7

1.7

-48.09%

1.4

-60.86%

2.6

-32.16%

Cu

31.43

3.6

-87.06%

15.8

-48.00%

0.05

-99.85%

Dy

3.61

3.48

8.91%

1.83

-47.56%

3.66

-2.12%

Er

1.94

1.82

5.99%

0.95

-49.35%

1.87

-6.94%

Eu

1.23

3.24

197.60%

1.82

53.06%

1.29

1.25%

Ga

17.23

17.4

14.09%

13.5

-18.95%

17.4

-2.50%

Gd

4.21

9.1

144.21%

2.34

-42.51%

4.38

0.44%

Ge

1.37

1

-17.53%

1.2

-9.39%

1.5

5.71%

Hf

4.67

5.7

37.90%

5.3

17.40%

5.3

9.57%

Hg

0.05

1.2

2611.49%

0.7

1348.18%

0.05

-3.45%

Ho

0.87

0.75

-2.60%

0.44

-47.68%

0.85

-5.67%

La

38.67

107

212.61%

22

-41.15%

22

-45.07%

Lu

0.3

0.3

12.98%

0.2

-31.04%

0.3

-3.45%

Mo

1.7

44.5

2857.38%

1.3

-20.90%

0.7

-60.25%

Nb

7

8

29.12%

8

18.22%

8

10.34%

Nd

27.8

75

204.80%

15

-44.19%

20.7

-28.11%

Ni

14.67

0.5

-96.15%

3

-78.85%

23

51.37%

Pb

12.46

8.79

-20.30%

12.2

1.28%

3.87

-70.01%

Pr

8.39

23.5

216.45%

4.38

-46.00%

5.82

-33.03%

Rb

178

350

122.15%

366

112.69%

189

2.51%

Sb

3.67

10

207.84%

11

210.04%

3

-21.08%

Sc

12.33

5

-54.19%

7

-41.27%

13

1.79%

Se

1.17

2

93.13%

1

-11.59%

1

-17.48%

Sm

4.84

12.8

198.79%

2.66

-43.15%

4.44

-11.43%

Sn

3.72

3.5

6.30%

10.8

200.31%

2.8

-27.33%

Sr

184.33

116

-28.90%

67

-62.40%

54

-71.72%

Ta

1.42

1.76

40.03%

1.34

-2.39%

1.24

-15.69%

Tb

0.65

0.96

66.86%

0.35

-44.30%

0.7

3.97%

Te

0.05

0.1

125.96%

0.05

3.44%

0.05

-3.45%

Th

17.97

22.9

43.97%

17.4

0.16%

15.5

-16.72%

Tl

0.01

0.005

-43.51%

0.005

-48.28%

0.005

-51.73%

Tm

0.35

0.29

-6.39%

0.16

-52.71%

0.29

-20.01%

U

6.02

10.8

102.69%

3.81

-34.53%

4.98

-20.13%

V

88.33

33

-57.79%

80

-6.31%

92

0.56%

W

11

244

2406.07%

194

1724.33%

6

-47.34%

Y

21.53

17.5

-8.17%

11

-47.15%

22.5

0.90%

Yb

2.07

1.84

0.43%

1

-50.03%

1.88

-12.32%
-51.97%

Zn

66.33

0.5

-99.15%

6

-90.64%

33

Zr

161.33

186

30.26%

188

20.54%

184

10.11%

Al 2O3 (wt.%)

15.93

14.1

0.00%

15.4

0.00%

16.5

0.00%

CaO

3.74

0.1

-96.98%

0.22

-93.92%

0.34

-91.22%

Fe2O3

5.85

2.82

-45.54%

4.25

-24.85%

5.81

-4.11%

MgO

2.13

0.18

-90.45%

0.25

-87.86%

2.24

1.53%

MnO

0.14

0.005

-95.97%

0.01

-92.61%

0.07

-51.73%

P2O5

0.11

0.08

-17.83%

0.12

12.85%

0.14

22.88%

K2O

4.21

11.4

205.93%

12.8

214.50%

8.58

96.76%

Na2O

3.13

0.13

-95.31%

0.22

-92.73%

0.35

-89.20%

TiO2

0.61

0.36

-33.32%

0.61

3.44%

0.63

-0.29%

SiO2

61.67

70

28.24%

65.1

9.19%

62.6

-2.00%

LOI

2.67

0.6

-74.61%

0.8

-69.01%

2.7

-2.37%

Mass change

12.98%

3.44%

- 218 -

-3.45%

Average Least Altered Andesite
0

Altered

96386
% Gain or Loss

Altered

96405
% Gain or Loss

Altered

96427
% Gain or Loss

Elements

Least altered Ci

Ci

ΔCi%

Ci

ΔCi%

Ci

ΔCi%

Au (ppb)

2.67

1

-63.40%

1

-59.41%

1

-59.69%

Ag (ppm)

0.05

0.05

-2.27%

0.05

8.37%

0.05

7.64%

As

8.17

4.7

-43.78%

4

-46.94%

3.8

-49.94%

Ba

767.67

1010

28.58%

407

-42.55%

521

-26.95%

Be

2

2.2

7.50%

2.5

35.46%

2

7.64%

Bi

0.32

1.3

297.03%

0.2

-32.27%

0.4

34.54%

Cd

0.15

0.1

-34.85%

0.1

-27.76%

0.05

-64.12%

Ce

70.67

92

27.23%

33

-49.40%

74

12.71%

Co

14.53

16.7

12.33%

4.1

-69.42%

7.7

-42.96%

Cr

90

54

-41.36%

31

-62.67%

104

24.38%

Cs

3.7

1.7

-55.10%

6.8

99.16%

1.4

-59.27%

Cu

31.43

88.6

175.50%

1.6

-94.48%

1.4

-95.21%

Dy

3.61

5.27

42.67%

4.59

37.79%

3.17

-5.48%

Er

1.94

2.78

40.05%

2.61

45.79%

1.55

-14.00%

Eu

1.23

1.4

11.24%

0.92

-18.94%

1.1

-3.74%

Ga

17.23

15.4

-12.65%

16.8

5.66%

15.3

-4.42%

Gd

4.21

5.6

30.00%

3.88

-0.13%

3.91

-0.03%

Ge

1.37

1.2

-14.40%

1.8

42.38%

1.4

9.99%

Hf

4.67

5.6

17.19%

6.3

46.19%

3.8

-12.42%

Hg

0.05

0.05

-2.27%

0.2

333.47%

0.1

115.27%

Ho

0.87

1.26

41.54%

1.16

44.49%

0.71

-12.16%

La

38.67

49

23.84%

14

-60.77%

38

5.77%

Lu

0.3

0.4

30.31%

0.4

44.49%

0.3

7.64%

Mo

1.7

1.5

-13.77%

0.8

-49.00%

13.9

780.08%

Nb

7

12

67.54%

11

70.29%

7

7.64%

Nd

27.8

37.5

31.83%

18.1

-29.44%

28.5

10.35%

Ni

14.67

4

-73.35%

2

-85.23%

7

-48.64%

Pb

12.46

10.7

-16.07%

3.68

-67.99%

8.03

-30.63%

Pr

8.39

11.2

30.46%

4.84

-37.49%

8.73

12.00%

Rb

178

243

33.42%

268

63.16%

124

-25.02%
-12.01%

Sb

3.67

4

6.52%

5

47.64%

3

Sc

12.33

12

-4.89%

9

-20.90%

12

4.75%

Se

1.17

0.5

-58.24%

0.5

-53.69%

0.5

-54.00%

Sm

4.84

6.72

35.69%

3.88

-13.13%

4.89

8.75%

Sn

3.72

0.05

-98.69%

2.8

-18.43%

0.05

-98.55%

Sr

184.33

111

-41.15%

8

-95.30%

81

-52.70%

Ta

1.42

2.07

42.47%

1.44

9.89%

1.36

3.09%

Tb

0.65

0.88

32.31%

0.74

23.37%

0.59

-2.30%

Te

0.05

0.05

-2.27%

0.05

8.37%

0.05

7.64%

Th

17.97

20

8.77%

14.9

-10.15%

16.5

-1.17%

Tl

0.01

0.005

-51.13%

0.005

-45.82%

0.005

-46.18%

Tm

0.35

0.48

34.03%

0.45

39.33%

0.28

-13.89%

U

6.02

5.88

-4.54%

3.62

-34.84%

4.57

-18.29%

V

88.33

120

32.77%

10

-87.73%

83

1.14%

W

11

6

-46.69%

26

156.14%

12

17.42%

Y

21.53

30

36.18%

26.7

34.39%

17

-15.01%

Yb

2.07

2.77

30.78%

2.81

47.11%

1.72

-10.56%

Zn

66.33

36

-46.96%

16

-73.86%

46

-25.35%

Zr

161.33

217

31.45%

207

39.04%

135

-9.93%

Al 2O3 (wt.%)

15.93

16.3

0.00%

14.7

0.00%

14.8

0.00%

CaO

3.74

2.26

-40.94%

0.2

-94.20%

2.08

-40.14%

Fe2O3

5.85

8.24

37.66%

6.2

14.85%

5.69

4.69%

MgO

2.13

1.48

-32.09%

0.76

-61.33%

1.63

-17.63%

MnO

0.14

0.1

-30.19%

0.02

-84.52%

0.12

-7.74%

P2O5

0.11

0.2

77.69%

0.08

-21.19%

0.1

-2.15%

K2O

4.21

6.74

56.46%

6.37

63.97%

3.82

-2.34%

Na2O

3.13

2.76

-13.82%

0.1

-96.54%

2.82

-3.03%

TiO2

0.61

0.99

58.61%

0.37

-34.27%

0.6

5.87%

SiO2

61.67

58.5

-7.29%

68

19.49%

67.2

17.29%

LOI

2.67

1.8

-34.11%

2.4

-2.59%

1.3

-47.59%

Mass change

-2.27%

8.37%

- 219 -

7.64%

Average Least Altered Andesite
0

Elements

Least altered Ci

97005

97030

97041

Altered

% Gain or Loss

Altered

% Gain or Loss

Altered

Ci

ΔCi%

Ci

ΔCi%

Ci

ΔCi%
-60.22%

% Gain or Loss

Au (ppb)

2.67

1

-66.48%

7

3063.94%

1

Ag (ppm)

0.05

0.05

-10.51%

0.05

1106.82%

0.05

6.20%

As

8.17

9.2

0.78%

10.2

1406.68%

1.9

-75.30%

Ba

767.67

120

-86.01%

11

-82.71%

1110

53.56%

Be

2

1.9

-14.98%

0.3

81.02%

1.7

-9.73%

Bi

0.32

0.2

-44.07%

9.3

34973.15%

0.05

-83.41%

Cd

0.15

0.1

-40.34%

0.3

2313.64%

0.05

-64.60%

Ce

70.67

96

21.57%

8

36.61%

99

48.77%

Co

14.53

4.6

-71.67%

21.5

1685.73%

6.9

-49.57%

Cr

90

143

42.20%

205

2648.86%

155

82.90%

Cs

3.7

0.2

-95.16%

0.05

-83.69%

0.5

-85.65%

Cu

31.43

1.9

-94.59%

101

3778.10%

0.5

-98.31%

Dy

3.61

4.31

6.85%

0.85

184.15%

3.16

-7.04%

Er

1.94

2.27

4.72%

0.45

179.93%

1.69

-7.49%

Eu

1.23

1.24

-9.78%

0.07

-31.32%

1.06

-8.48%

Ga

17.23

18.3

-4.95%

2.2

54.09%

15.6

-3.85%

Gd

4.21

5.2

10.54%

0.7

100.66%

3.7

-6.67%

Ge

1.37

1.2

-21.61%

0.7

516.62%

0.9

-30.23%

Hf

4.67

6.2

18.81%

0.6

55.05%

5.5

25.07%

Hg

0.05

0.05

-10.51%

0.05

1106.82%

0.05

6.20%

Ho

0.87

0.98

0.81%

0.2

177.43%

0.69

-15.77%

La

38.67

53

22.66%

4

24.83%

50

37.32%

Lu

0.3

0.3

-10.51%

0.1

302.27%

0.3

6.20%

Mo

1.7

0.5

-73.68%

85.7

60737.83%

0.3

-81.26%

Nb

7

10

27.85%

2

244.81%

10

51.71%

Nd

27.8

36.8

18.47%

2.6

12.87%

32.4

23.77%

Ni

14.67

14

-14.59%

6

393.59%

14

1.35%

Pb

12.46

4.62

-66.82%

49.1

4655.60%

4.12

-64.88%

Pr

8.39

10.7

14.13%

0.89

28.02%

10.5

32.91%

Rb

178

24.2

-87.83%

10.2

-30.85%

182

8.59%

Sb

3.67

4

-2.46%

2

557.67%

1

-71.06%

Sc

12.33

15

8.87%

1

-2.12%

5

-56.93%

Se

1.17

1

-23.51%

0.5

415.73%

0.5

-54.62%

Sm

4.84

6.53

20.74%

0.52

29.66%

4.85

6.42%

Sn

3.72

13.2

217.56%

5.4

1651.83%

9.5

171.21%

Sr

184.33

108

-47.56%

5

-67.26%

70

-59.67%

Ta

1.42

1.42

-10.51%

0.42

256.95%

1.76

31.63%

Tb

0.65

0.82

12.90%

0.14

159.93%

0.58

-5.24%

Te

0.05

0.05

-10.51%

0.05

1106.82%

0.05

6.20%

Th

17.97

16.7

-16.83%

3.96

165.94%

25.4

50.11%

Tl

0.01

0.005

-55.25%

0.005

503.41%

0.005

-46.90%

Tm

0.35

0.35

-10.51%

0.08

175.84%

0.3

-8.97%

U

6.02

6.98

3.77%

3.93

687.84%

8.21

44.83%

V

88.33

94

-4.76%

6

-18.02%

33

-60.32%

W

11

0.5

-95.93%

1

9.71%

4

-61.38%

Y
Yb

21.53
2.07

23.1
2.28

-3.98%
-1.43%

5.69
0.52

218.94%
203.16%

17.8
2.04

-12.20%
4.66%
-11.94%

Zn

66.33

19

-74.36%

99

1701.22%

55

Zr

161.33

188

4.29%

13

-2.75%

154

1.37%

Al 2O3 (wt.%)

15.93

17.8

0.00%

1.32

0.00%

15

0.00%

CaO

3.74

3.29

-21.27%

0.04

-87.09%

0.28

-92.05%

Fe2O3

5.85

3.03

-53.65%

2.6

436.36%

3.12

-43.36%

MgO

2.13

2.27

-4.62%

0.56

217.29%

1.19

-40.67%

MnO

0.14

0.06

-61.65%

0.02

72.40%

0.07

-46.90%

P2O5

0.11

0.16

30.17%

0.005

-45.14%

0.04

-61.38%

K2O

4.21

0.68

-85.54%

0.005

-98.57%

6.4

61.44%

Na2O

3.13

8.61

146.18%

0.005

-98.07%

3.54

20.11%

TiO2

0.61

0.71

4.17%

0.02

-60.43%

0.36

-37.32%

SiO2

61.67

62.1

-9.88%

93.6

1731.66%

68.5

17.96%

LOI

2.67

1

-66.48%

1.5

577.99%

1

-60.22%

Mass change

-10.51%

- 220 -

1106.82%

6.20%

Average Least Altered Andesite
0

Altered

97063
% Gain or Loss

Altered

97094
% Gain or Loss

Altered

97095
% Gain or Loss

Elements

Least altered Ci

Ci

ΔCi%

Ci

ΔCi%

Ci

ΔCi%

Au (ppb)

2.67

29

36713.29%

38

1554.88%

1

-62.24%

Ag (ppm)

0.05

0.05

3289.36%

0.4

830.22%

0.05

0.82%

As

8.17

685

284075.37%

34.2

386.74%

5.8

-28.42%

Ba

767.67

534

2257.68%

70

-89.40%

77

-89.89%

Be

2

2.1

3458.83%

2.2

27.91%

1.8

-9.26%

Bi

0.32

42.3

447931.25%

31.7

11418.73%

0.3

-5.48%

Cd

0.15

0.1

2159.57%

0.1

-22.48%

0.05

-66.39%

Ce

70.67

25

1099.01%

118

94.15%

96

36.96%

Co

14.53

39.3

9067.37%

11.7

-6.37%

3.3

-77.10%

Cr

90

197

7318.94%

144

86.04%

144

61.32%

Cs

3.7

0.05

-54.20%

0.3

-90.57%

0.1

-97.28%

Cu

31.43

265

28477.18%

4490

16511.05%

201

544.78%

Dy

3.61

0.92

763.77%

4.98

60.40%

3.7

3.34%

Er

1.94

0.46

703.66%

2.5

49.84%

1.94

0.82%

Eu

1.23

0.36

892.01%

1.52

43.69%

0.86

-29.51%

Ga

17.23

3.9

667.18%

14.7

-0.80%

15.9

-6.96%

Gd

4.21

0.94

656.77%

6.26

72.90%

4.48

7.29%

Ge

1.37

2.1

5095.37%

1.3

10.34%

1.1

-19.05%

Hf

4.67

0.3

117.73%

5.4

34.45%

6.5

40.33%

Hg

0.05

0.9

60908.51%

1.8

4085.99%

0.05

0.82%

Ho

0.87

0.22

757.08%

1.09

45.68%

0.86

-0.34%

La

38.67

20

1652.97%

47

41.32%

44

14.72%

Lu

0.3

0.1

1029.79%

0.4

55.04%

0.4

34.43%

Mo

1.7

60.6

120720.78%

1.1

-24.76%

0.8

-52.55%

Nb
Nd

7
27.8

0.5
4.4

142.10%
436.45%

9
46

49.50%
92.40%

10
34

44.03%
23.31%

Ni

14.67

39

8910.57%

10

-20.74%

5

-65.64%

Pb

12.46

22.9

6129.24%

5.17

-51.75%

2.45

-80.18%

Pr

8.39

1.66

570.60%

14.2

96.80%

10.5

26.18%

Rb

178

3.4

-35.26%

14.3

-90.66%

9.3

-94.73%

Sb

3.67

12

10982.38%

4

26.73%

2

-45.06%

Sc

12.33

1

174.89%

6

-43.42%

7

-42.76%

Se

1.17

0.5

1348.45%

1

-0.62%

0.5

-56.91%

Sm

4.84

0.7

390.20%

7.84

88.35%

5.51

14.78%

Sn

3.72

7.1

6368.94%

11.2

250.08%

8.8

138.51%

Sr

184.33

26

378.07%

25

-84.23%

21

-88.51%

Ta

1.42

0.03

-28.39%

1.36

11.36%

1.41

0.11%

Tb

0.65

0.15

682.16%

0.97

73.52%

0.68

5.48%

Te
Th

0.05
17.97

3.7
0.44

250712.77%
-17.01%

0.2
17.5

365.11%
13.24%

0.05
17.9

0.82%
0.43%

Tl

0.01

0.005

1594.68%

0.005

-41.86%

0.005

-49.59%

Tm

0.35

0.08

674.71%

0.44

46.18%

0.35

0.82%

U

6.02

8.04

4426.66%

6.3

21.69%

6.54

9.53%

V

88.33

138

5195.28%

32

-57.88%

26

-70.32%
-45.01%

W

11

152

46734.82%

296

3028.92%

6

Y

21.53

4.81

657.21%

26.5

43.12%

21.2

-0.72%

Yb

2.07

0.54

784.18%

2.64

48.30%

2.36

14.95%

Zn

66.33

23

1075.26%

8

-85.98%

0.5

-99.24%

Zr

161.33

15

215.13%

159

14.60%

189

18.12%

Al 2O3 (wt.%)

15.93

0.47

0.00%

13.7

0.00%

15.8

0.00%

CaO

3.74

0.09

-18.44%

1.26

-60.83%

0.9

-75.74%

Fe2O3

5.85

56.2

32461.05%

5.04

0.18%

2.22

-61.74%

MgO

2.13

0.11

75.04%

1.15

-37.22%

0.54

-74.44%

MnO

0.14

0.02

384.19%

0.04

-66.78%

0.02

-85.60%

P2O5

0.11

0.005

54.06%

0.14

47.99%

0.07

-35.84%

K2O

4.21

0.13

4.66%

0.59

-83.70%

0.43

-89.70%

Na2O

3.13

0.005

-94.59%

7.33

172.30%

8.98

189.26%

TiO2

0.61

0.06

233.38%

0.38

-27.56%

0.43

-28.93%

SiO2

61.67

42.3

2224.79%

68.9

29.91%

70

14.44%

LOI

2.67

0.6

661.65%

1.6

-30.32%

0.4

-84.90%

Mass change

3289.36%

- 221 -

16.28%

0.82%

Average Least Altered Andesite
Elements

0
Least altered Ci

97099

97249

97254

Altered

% Gain or Loss

Altered

% Gain or Loss

Altered

Ci

ΔCi%

Ci

ΔCi%

Ci

ΔCi%

906.36%

13

470.31%

2

-1.38%

% Gain or Loss

Au (ppb)

2.67

28

Ag (ppm)

0.05

0.05

-4.04%

0.8

1774.12%

0.05

31.65%

As

8.17

16.7

96.16%

10.7

53.40%

20.2

225.51%

Ba

767.67

69

-91.37%

421

-35.76%

19

-96.74%

Be

2

2.7

29.55%

2.6

52.27%

0.4

-73.67%

Bi

0.32

1.2

259.86%

0.9

229.43%

8.6

3438.17%

Cd
Ce

0.15
70.67

0.05
66

-68.01%
-10.38%

0.1
43

-21.91%
-28.73%

0.05
4

-56.12%
-92.55%

Co

14.53

4.8

-68.30%

18.8

51.55%

94.1

752.62%

Cr

90

137

46.08%

126

63.99%

136

98.94%

Cs

3.7

0.2

-94.81%

2.8

-11.36%

0.2

-92.88%

Cu

31.43

1810

5426.39%

974

3529.87%

4.1

-82.83%

Dy

3.61

4.12

9.52%

2.3

-25.37%

3.79

38.22%

Er

1.94

2.19

8.33%

1.4

-15.47%

1.68

14.01%

Eu

1.23

0.87

-32.12%

0.93

-11.44%

0.46

-50.76%

Ga

17.23

16.8

-6.43%

13

-11.62%

33.6

156.73%

Gd

4.21

4.53

3.26%

2.44

-32.11%

2.32

-27.45%

Ge

1.37

1.3

-8.94%

1

-14.50%

1.2

15.32%

Hf

4.67

5.7

17.13%

5.7

42.97%

3.1

-12.61%

Hg

0.05

0.05

-4.04%

0.2

368.53%

0.3

689.92%

Ho

0.87

0.98

8.10%

0.53

-28.64%

0.8

21.06%

La

38.67

23

-42.92%

22

-33.36%

1

-96.60%

Lu

0.3

0.4

27.95%

0.2

-21.91%

0.2

-12.23%

Mo

1.7

1.4

-20.97%

0.05

-96.55%

29.6

2192.31%
-81.19%

Nb

7

9

23.38%

10

67.33%

1

Nd

27.8

31

7.01%

17.5

-26.27%

2.5

-88.16%

Ni

14.67

16

4.66%

18

43.72%

72

546.15%

Pb

12.46

3.16

-75.66%

7.98

-24.98%

8.03

-15.15%

Pr

8.39

8.88

1.57%

4.97

-30.61%

0.53

-91.68%

Rb

178

11.5

-93.80%

290

90.83%

4.2

-96.89%

Sb

3.67

1

-73.85%

2

-36.17%

2

-28.25%

Sc

12.33

13

1.18%

9

-14.50%

19

102.87%

Se

1.17

1

-17.98%

0.5

-49.94%

0.5

-43.74%

Sm

4.84

5.48

8.65%

2.87

-30.54%

1.21

-67.09%

Sn
Sr

3.72
184.33

8.2
26

111.53%
-86.46%

11.2
138

252.66%
-12.31%

18.1
95

540.57%
-32.15%

Ta

1.42

1.33

-10.12%

1.91

57.55%

0.43

-60.13%

Tb

0.65

0.73

7.77%

0.38

-31.52%

0.56

13.42%

Te

0.05

0.05

-4.04%

0.1

134.26%

2.4

6219.34%

Th

17.97

15.3

-18.29%

22.4

46.01%

5.31

-61.10%

Tl

0.01

0.005

-52.02%

0.005

-41.43%

0.005

-34.17%

Tm

0.35

0.38

4.19%

0.22

-26.37%

0.26

-2.20%

U

6.02

5.87

-6.43%

11.7

127.65%

4.67

2.13%

V

88.33

58

-36.99%

46

-39.00%

91

35.63%

W

11

3

-73.83%

32

240.75%

39

366.77%

Y

21.53

22.8

1.62%

13.3

-27.64%

20.7

26.58%

Yb

2.07

2.48

14.97%

1.52

-13.99%

1.53

-2.69%

Zn

66.33

4

-94.21%

3

-94.70%

4

-92.06%

Zr

161.33

167

-0.66%

180

30.69%

110

-10.23%

Al 2O3 (wt.%)

15.93

16.6

0.00%

13.6

0.00%

12.1

0.00%

CaO

3.74

1.38

-64.59%

3.54

10.87%

2.13

-25.02%

Fe2O3

5.85

3.91

-35.86%

4.46

-10.70%

17.9

302.84%

MgO

2.13

1.38

-37.83%

1.25

-31.26%

3.38

108.91%

MnO

0.14

0.03

-79.44%

0.02

-83.27%

0.14

31.65%

P2O5

0.11

0.12

4.69%

0.13

38.43%

0.08

-4.25%

K2O

4.21

0.63

-85.64%

4.54

26.31%

0.14

-95.62%

Na2O

3.13

9.25

183.60%

2.43

-9.06%

1.02

-57.10%

TiO2

0.61

0.5

-21.34%

0.59

13.29%

0.38

-17.99%

SiO2

61.67

65.1

1.30%

66.4

26.12%

61

30.22%

LOI

2.67

1.1

-60.46%

2.5

9.67%

3.5

72.58%

Mass change

-4.04%

17.13%

- 222 -

31.65%

97266

Average Least Altered Andesite
0

Elements

Least altered Ci

98032

98172

Altered

% Gain or Loss

Altered

% Gain or Loss

Altered

Ci

ΔCi%

Ci

ΔCi%

Ci

ΔCi%

-26.88%

1

389.04%

11

315.37%

% Gain or Loss

Au (ppb)

2.67

1

Ag (ppm)

0.05

0.05

95.22%

0.1

2511.48%

0.2

303.29%

As

8.17

52.6

1156.87%

0.6

-4.11%

13.4

65.36%

Ba

767.67

11

-97.20%

29

-50.67%

798

4.81%

Be

2

0.5

-51.19%

0.2

30.57%

1.8

-9.26%

Bi

0.32

0.7

327.05%

0.2

716.09%

0.9

183.56%

Cd

0.15

0.2

160.29%

0.05

335.25%

0.2

34.43%

Ce

70.67

3

-91.71%

2

-63.05%

67

-4.41%

Co

14.53

91.3

1126.68%

0.6

-46.08%

8.8

-38.94%

Cr

90

205

344.67%

254

3585.08%

115

28.83%

Cs

3.7

0.2

-89.45%

0.1

-64.71%

0.8

-78.20%

Cu

31.43

2.5

-84.47%

25.3

951.07%

150

381.18%

Dy

3.61

1.55

-16.18%

0.17

-38.51%

3.22

-10.07%

Er

1.94

0.9

-9.43%

0.1

-32.69%

1.67

-13.21%

Eu

1.23

0.22

-65.08%

0.04

-57.54%

1.16

-4.92%

Ga

17.23

18.3

107.34%

1.1

-16.64%

14.4

-15.74%

Gd

4.21

0.96

-55.48%

0.19

-41.07%

3.83

-8.28%

Ge

1.37

1.1

56.75%

0.3

185.93%

1.3

-4.33%

Hf

4.67

6.2

159.18%

0.3

-16.12%

4.6

-0.69%

Hg

0.05

0.1

290.44%

0.05

1205.74%

0.05

0.82%

Ho

0.87

0.37

-16.98%

0.04

-39.97%

0.78

-9.61%

La

38.67

1

-94.95%

1

-66.23%

33

-13.96%

Lu

0.3

0.2

30.15%

0

-100.00%

0.3

0.82%

Mo

1.7

0.05

-94.26%

0.05

-61.60%

1.4

-16.97%

Nb

7

10

178.89%

0.5

-6.73%

7

0.82%

Nd

27.8

2.1

-85.25%

0.8

-62.42%

25.4

-7.88%

Ni

14.67

33

339.15%

14

1146.10%

25

71.82%

Pb

12.46

4.96

-22.29%

0.654

-31.46%

29.5

138.71%

Pr
Rb

8.39
178

0.45
3.8

-89.53%
-95.83%

0.27
12.6

-57.98%
-7.57%

7.31
162

-12.16%
-8.24%

Sb

3.67

3

59.58%

1

255.79%

4

9.89%

Sc

12.33

12

90.00%

1

5.90%

12

-1.88%

Se

1.17

0.5

-16.57%

0.5

458.01%

0.5

-56.91%

Sm

4.84

0.65

-73.78%

0.21

-43.35%

4.34

-9.59%

Sn

3.72

17

792.14%

2.3

707.31%

12

225.23%

Sr

184.33

61

-35.40%

4

-71.67%

171

-6.47%

Ta

1.42

1.99

173.58%

0.12

10.34%

1.14

-19.06%

Tb

0.65

0.22

-33.93%

0.03

-39.74%

0.57

-11.59%

Te

0.05

1.8

6927.94%

0.1

2511.48%

0.05

0.82%

Th

17.97

12.4

34.71%

1.51

9.72%

15.7

-11.91%

Tl

0.01

0.005

-2.39%

0.005

552.87%

0.005

-49.59%

Tm

0.35

0.19

5.98%

0.02

-25.39%

0.28

-19.34%

U

6.02

5.52

79.01%

0.39

-15.41%

4.62

-22.62%

V

88.33

73

61.34%

3

-55.65%

89

1.59%

W

11

18

219.45%

0.5

-40.65%

7

-35.84%

Y

21.53

10.3

-6.61%

1.09

-33.89%

20.4

-4.47%

Yb

2.07

1.28

20.72%

0.13

-18.00%

1.77

-13.79%
21.60%

Zn

66.33

11

-67.63%

2

-60.63%

80

Zr

161.33

212

156.53%

12

-2.88%

154

-3.76%

Al 2O3 (wt.%)

15.93

8.16

0.00%

1.22

0.00%

15.8

0.00%

CaO

3.74

0.39

-79.64%

0.06

-79.05%

3.45

-7.00%

Fe2O3

5.85

6.88

129.59%

0.48

7.14%

5.49

-5.38%

MgO

2.13

2.22

103.47%

0.08

-50.96%

1.5

-29.00%

MnO

0.14

0.005

-93.03%

0.005

-53.37%

0.09

-35.19%

P2O5

0.11

0.1

77.47%

0.005

-40.65%

0.11

0.82%

K2O

4.21

0.11

-94.90%

0.52

61.28%

4.86

16.39%

Na2O

3.13

0.66

-58.84%

0.08

-66.63%

3.38

8.88%

TiO2

0.61

0.58

85.62%

0.03

-35.78%

0.62

2.48%

SiO2

61.67

79

150.08%

96.5

1943.19%

63.3

3.49%

LOI

2.67

2.2

60.86%

0.4

95.62%

1.1

-58.46%

Mass change

95.22%

1205.74%

- 223 -

0.82%

Average Least Altered Andesite
0

Altered

98185
% Gain or Loss

Altered

98207
% Gain or Loss

Elements

Least altered Ci

Ci

ΔCi%

Ci

ΔCi%

Au (ppb)

2.67

1

-61.51%

4

52.98%

Ag (ppm)

0.05

0.05

2.77%

0.3

512.69%

As

8.17

3.6

-54.71%

81.2

914.90%

Ba

767.67

486

-34.94%

762

1.36%

Be

2

3.6

84.99%

2.6

32.75%

Bi

0.32

15.6

4910.24%

1.4

346.75%

Cd

0.15

0.2

37.03%

0.2

36.15%

Ce

70.67

80

16.34%

79

14.15%

Co

14.53

10.4

-26.44%

9.2

-35.34%

Cr

90

108

23.33%

93

5.52%

Cs

3.7

1.5

-58.33%

2.6

-28.24%

Cu

31.43

262

756.72%

143

364.60%

Dy

3.61

4.76

35.51%

5.06

43.13%

Er

1.94

2.73

44.63%

2.8

47.38%

Eu

1.23

2.15

79.65%

1.19

-1.21%

Ga

17.23

15.6

-6.95%

16.4

-2.80%

Gd

4.21

5.1

24.50%

5.25

27.34%

Ge

1.37

1.6

20.03%

1.2

-10.56%

Hf

4.67

5.3

16.64%

5.9

29.01%

Hg

0.05

0.8

1544.39%

0.05

2.12%

Ho

0.87

1.16

37.03%

1.25

46.72%

La

38.67

43

14.28%

38

0.35%

Lu

0.3

0.5

71.29%

0.4

36.15%

Mo

1.7

15.2

818.92%

4.5

170.31%

Nb

7

7

2.77%

10

45.88%

Nd

27.8

30.1

11.28%

32.2

18.28%

Ni

14.67

23

61.13%

8

-44.31%

Pb

12.46

14.8

22.08%

17.9

46.70%

Pr

8.39

9.09

11.35%

8.93

8.69%

Rb
Sb

178
3.67

177
8

2.20%
124.03%

201
7

15.31%
94.77%

Sc

12.33

11

-8.31%

15

24.23%

Se

1.17

0.5

-56.08%

0.5

-56.36%

Sm

4.84

5.88

24.86%

5.9

24.48%

Sn

3.72

140

3767.85%

3.7

1.57%

Sr

184.33

167

-6.89%

141

-21.89%

Ta

1.42

1.25

-9.53%

1.54

10.74%

Tb

0.65

0.81

28.07%

0.81

27.25%

Te

0.05

0.1

105.55%

0.2

308.46%

Th

17.97

19.4

10.95%

18.4

4.56%

Tl

0.01

0.005

-48.61%

0.005

-48.94%

Tm

0.35

0.48

40.95%

0.47

37.13%

U

6.02

10.6

80.96%

5.21

-11.62%

V

88.33

72

-16.23%

19

-78.03%

W

11

113

955.77%

11

2.12%

Y

21.53

29.5

40.82%

31.1

47.51%

Yb

2.07

3.42

69.80%

2.93

44.54%

Zn

66.33

108

67.34%

17

-73.83%

Zr

161.33

175

11.48%

187

18.36%

Al 2O3 (wt.%)

15.93

15.5

0.00%

15.6

0.00%

CaO

3.74

2.71

-25.53%

3.49

-4.71%

Fe2O3

5.85

5.22

-8.29%

3.08

-46.24%

MgO

2.13

2.15

3.74%

0.61

-70.76%

MnO

0.14

0.13

-4.57%

0.05

-63.53%

P2O5

0.11

0.09

-15.91%

0.1

-7.17%

K2O

4.21

2.96

-27.74%

5.24

27.10%

Na2O

3.13

3.16

3.76%

1.77

-42.25%

TiO2

0.61

0.57

-3.97%

0.48

-19.65%

SiO2

61.67

65.3

8.82%

68.4

13.26%

LOI

2.67

2

-23.02%

1.6

-38.81%

Mass change

2.77%

2.12%

- 224 -

Least Altered Basaltic Andesite
0

Altered

98191
% Gain or Loss

Altered

98271
% Gain or Loss

Elements

Least altered Ci

Ci

ΔCi%

Ci

ΔCi%

Au (ppb)

1

1

-2.26%

1

6.79%

Ag (ppm)

0.05

0.05

-2.26%

0.05

6.79%

As

4.6

10.4

120.98%

10.2

136.80%

Ba

248

1060

317.76%

188

-19.05%

Be

2.1

2

-6.91%

2.1

6.79%

Bi

0.3

1.6

421.28%

0.4

42.39%

Cd

0.05

0.2

290.96%

0.1

113.58%

Ce

43

70

59.11%

68

68.88%

Co

20.9

15.1

-29.38%

13

-33.58%

Cr

175

63

-64.81%

223

36.08%

Cs

1.4

1.7

18.68%

0.3

-77.12%

Cu

5

7

36.84%

1.3

-72.23%

Dy

2.87

3.78

28.73%

3.22

19.81%

Er

1.48

1.82

20.19%

1.63

17.61%

Eu

0.94

1.6

66.37%

1.07

21.56%

Ga

15.3

16.2

3.49%

17.8

24.24%

Gd

3.19

4.32

32.36%

3.92

31.23%

Ge

1.4

1.8

25.67%

1.9

44.93%

Hf

3.1

3.8

19.81%

3.3

13.68%

Hg

0.05

0.05

-2.26%

0.2

327.16%

Ho

0.66

0.87

28.84%

0.75

21.35%

La

21

34

58.25%

35

77.98%

Lu

0.2

0.3

46.61%

0.2

6.79%

Mo

1.3

2.3

72.92%

0.5

-58.93%
-14.57%

Nb

5

5

-2.26%

4

Nd

19.2

28.2

43.56%

27.9

55.18%

Ni

39

17

-57.40%

25

-31.54%

Pb

5.7

13.6

133.20%

16.6

211.00%

Pr

5.13

7.94

51.28%

8.23

71.32%

Rb

146

193

29.20%

43.5

-68.18%

Sb

1

9

779.66%

7

647.53%

Sc
Se

23
0.5

20
0.5

-15.01%
-2.26%

22
1

2.15%
113.58%

Sm

3.73

5.18

35.74%

4.79

37.14%

Sn

6.3

4.4

-31.74%

20.9

254.27%
70.44%

Sr

203

318

53.11%

324

Ta

0.75

0.88

14.68%

0.64

-8.87%

Tb

0.47

0.67

39.33%

0.62

40.87%

Te

0.05

0.05

-2.26%

0.05

6.79%

Th

9.48

11.7

20.63%

7.64

-13.94%

Tl

0.005

0.005

-2.26%

0.005

6.79%

Tm

0.24

0.29

18.10%

0.26

15.69%

U

2.12

4.56

110.23%

4.12

107.54%

V

127

159

22.37%

177

48.83%

W

4

10

144.35%

19

407.25%

Y

17.9

21.2

15.76%

16.8

0.23%

Yb

1.53

1.88

20.10%

1.69

17.96%

Zn

28

52

81.52%

16

-38.98%

Zr

101

122

18.06%

92

-2.73%

Al 2O3 (wt.%)

17.3

17.7

0.00%

16.2

0.00%

CaO

7.45

8.21

7.71%

11.7

67.71%

Fe2O3

8.82

7.65

-15.23%

9.38

13.57%

MgO

4.25

2.99

-31.24%

2.78

-30.15%

MnO

0.1

0.21

105.25%

0.28

199.01%

P2O5

0.08

0.08

-2.26%

0.09

20.14%

K2O

2.3

4.5

91.23%

1.3

-39.64%

Na2O

2.82

2.55

-11.62%

0.74

-71.98%

TiO2

0.68

0.75

7.80%

0.68

6.79%

SiO2

54.2

53.8

-2.98%

54.7

7.78%

LOI

1.6

1.5

-8.37%

2.3

53.51%

Mass change

-2.26%

6.79%

- 225 -

Least Altered Dacite
0

Altered

96392
% Gain or Loss

Altered

97227
% Gain or Loss

Altered

97228
% Gain or Loss

Elements

Least altered Ci

Ci

ΔCi%

Ci

ΔCi%

Ci

ΔCi%

Au (ppb)

1

13

1022.11%

1

1.23%

3

198.18%

Ag (ppm)

0.2

0.05

-78.42%

0.8

304.94%

0.3

49.09%

As

5.5

13.3

108.73%

9

65.66%

47.1

751.17%

Ba

867

2800

178.76%

2230

160.38%

3320

280.61%

Be

2.6

2.1

-30.28%

1.7

-33.81%

1.3

-50.30%

Bi

0.1

14.2

12156.84%

0.5

406.17%

0.4

297.58%

Cd

0.2

0.2

-13.68%

0.3

51.85%

0.2

-0.61%

Ce

106

108

-12.06%

74

-29.33%

63

-40.93%

Co

10.1

21.2

81.18%

19

90.44%

63.6

525.89%

Cr

73

46

-45.61%

115

59.48%

105

42.96%

Cs

2.4

2.6

-6.49%

1.3

-45.16%

1.2

-50.30%

Cu

18.2

36.5

73.11%

12.6

-29.91%

7.2

-60.68%

Dy

5.47

6.58

3.83%

3.6

-33.37%

2.57

-53.30%

Er

2.66

3.53

14.55%

1.95

-25.79%

1.56

-41.71%

Eu

1.76

1.86

-8.78%

1.45

-16.60%

1.32

-25.45%

Ga

19

19

-13.68%

19.2

2.30%

19.5

2.01%

Gd

6.17

7.12

-0.39%

4.2

-31.09%

3.08

-50.38%

Ge

1.5

0.6

-65.47%

1.2

-19.01%

1.1

-27.11%

Hf

7.6

8.7

-1.19%

7.5

-0.10%

7.4

-3.22%

Hg

0.05

0.05

-13.68%

0.2

304.94%

0.2

297.58%

Ho

1.31

1.62

6.74%

0.84

-35.09%

0.61

-53.72%

La

50

54

-6.78%

38

-23.06%

35

-30.42%

Lu

0.4

0.6

29.47%

0.4

1.23%

0.4

-0.61%

Mo

2.3

3.1

16.34%

10.6

366.56%

6

159.29%

Nb

10

15

29.47%

10

1.23%

10

-0.61%

Nd

41

45.2

-4.84%

29.1

-28.15%

22.8

-44.73%

Ni

10

13

12.21%

15

51.85%

19

88.85%

Pb

17.2

10.2

-48.81%

12.7

-25.25%

7.42

-57.12%

Pr

12.1

13.2

-5.84%

8.85

-25.96%

7.17

-41.10%

Rb

176

462

126.58%

232

33.45%

286

61.52%

Sb

5

4

-30.95%

6

21.48%

6

19.27%

Sc
Se

11
0.5

13
0.5

2.01%
-13.68%

15
0.5

38.05%
1.23%

18
0.5

62.64%
-0.61%

Sm

7.29

8.44

-0.07%

5.11

-29.04%

3.84

-47.64%

Sn

2.3

0.05

-98.12%

15.5

582.23%

17.1

638.97%
-54.82%

Sr

231

159

-40.59%

106

-53.55%

105

Ta

1.61

2.56

37.25%

1.47

-7.57%

1.56

-3.69%

Tb

1

1.13

-2.46%

0.65

-34.20%

0.46

-54.28%

Te

0.1

11.4

9740.00%

0.05

-49.38%

0.3

198.18%

Th

21.8

26.3

4.13%

17.5

-18.73%

17.3

-21.12%

Tl

0.005

0.005

-13.68%

0.005

1.23%

0.005

-0.61%

Tm

0.51

0.62

4.93%

0.36

-28.54%

0.31

-39.58%

U

6.69

7.42

-4.27%

6.38

-3.46%

6.32

-6.10%

V

57

68

2.97%

71

26.10%

81

41.24%

W

6

7

0.70%

40

574.90%

32

430.10%

Y

29.7

38.2

11.02%

21.4

-27.06%

15.9

-46.79%

Yb

2.8

3.76

15.91%

2.4

-13.23%

2.04

-27.58%

Zn

42

26

-46.57%

9

-78.31%

0.5

-98.82%

Zr

257

338

13.52%

260

2.42%

258

-0.22%

Al 2O3 (wt.%)

16.4

19

0.00%

16.2

0.00%

16.5

0.00%

CaO

3.44

1.35

-66.13%

0.68

-79.99%

0.53

-84.69%

Fe2O3

5.61

4.57

-29.69%

6.03

8.81%

5.27

-6.63%

MgO

1.45

1.84

9.53%

1.13

-21.11%

1.24

-15.00%

MnO

0.05

0.06

3.58%

0.02

-59.51%

0.005

-90.06%

P2O5

0.22

0.27

5.93%

0.22

1.23%

0.23

3.91%

K2O

4.86

9.46

68.01%

8.28

72.47%

9.53

94.90%

Na2O

2.94

2.1

-38.35%

1.72

-40.77%

1.07

-63.83%

TiO2

0.84

0.98

0.70%

0.78

-6.00%

0.82

-2.97%

SiO2

62.8

53.8

-26.05%

64.4

3.81%

63.3

0.19%

LOI

1.4

2.2

35.64%

0.9

-34.92%

1.8

27.79%

Mass change

-13.68%

- 226 -

1.23%

-0.61%

Least Altered Dacite
0

Altered

97258
% Gain or Loss

Altered

98098
% Gain or Loss

Elements

Least altered Ci

Ci

ΔCi%

Ci

ΔCi%

Au (ppb)

1

1

22.39%

1

0.00%

Ag (ppm)

0.2

0.05

-69.40%

0.2

0.00%

As

5.5

22.5

400.68%

3.1

-43.64%

Ba

867

593

-16.29%

1450

67.24%

Be

2.6

0.8

-62.34%

1.8

-30.77%

Bi

0.1

0.4

389.55%

0.05

-50.00%

Cd

0.2

0.1

-38.81%

0.2

0.00%

Ce

106

17

-80.37%

107

0.94%

Co

10.1

91.6

1009.97%

8.8

-12.87%

Cr

73

138

131.36%

123

68.49%

Cs

2.4

0.6

-69.40%

2

-16.67%

Cu

18.2

54

263.13%

1.3

-92.86%

Dy

5.47

3.2

-28.40%

4.31

-21.21%

Er

2.66

1.66

-23.62%

2.44

-8.27%

Eu

1.76

0.77

-46.46%

1.88

6.82%

Ga

19

28.7

84.87%

15.2

-20.00%

Gd

6.17

2.69

-46.64%

5.18

-16.05%

Ge

1.5

1.4

14.23%

1.1

-26.67%

Hf

7.6

6.2

-0.16%

5.5

-27.63%

Hg

0.05

19.1

46652.24%

0.2

300.00%

Ho

1.31

0.75

-29.93%

1.09

-16.79%

La

50

8

-80.42%

52

4.00%

Lu

0.4

0.3

-8.21%

0.4

0.00%

Mo

2.3

10.8

474.69%

1.1

-52.17%

Nb

10

7

-14.33%

10

0.00%

Nd

41

9.5

-71.64%

40.5

-1.22%

Ni

10

31

279.40%

23

130.00%

Pb

17.2

4.39

-68.76%

5.58

-67.56%

Pr

12.1

2.38

-75.93%

12.2

0.83%

Rb

176

103

-28.38%

304

72.73%

Sb

5

4

-2.09%

6

20.00%

Sc
Se

11
0.5

11
0.5

22.39%
22.39%

22
0.5

100.00%
0.00%

Sm

7.29

2.46

-58.70%

7.22

-0.96%

Sn

2.3

23.1

1129.20%

4.3

86.96%
-64.50%

Sr

231

82

-56.55%

82

Ta

1.61

1.24

-5.74%

1.94

20.50%

Tb

1

0.5

-38.81%

0.76

-24.00%

Te

0.1

0.4

389.55%

0.05

-50.00%

Th

21.8

18.3

2.74%

24

10.09%

Tl

0.005

0.005

22.39%

0.005

0.00%

Tm

0.51

0.3

-28.01%

0.47

-7.84%

U

6.69

9.58

75.26%

8.66

29.45%

V

57

69

48.15%

150

163.16%

W

6

2720

55382.59%

23

283.33%

Y

29.7

18

-25.83%

25.2

-15.15%

Yb

2.8

1.86

-18.70%

2.63

-6.07%

Zn

42

1

-97.09%

40

-4.76%

Zr

257

213

1.43%

183

-28.79%

Al 2O3 (wt.%)

16.4

13.4

0.00%

16.4

0.00%

CaO

3.44

1.01

-64.07%

1.56

-54.65%

Fe2O3

5.61

15.6

240.33%

7.2

28.34%

MgO

1.45

2.15

81.47%

2.39

64.83%

MnO

0.05

0.06

46.87%

0.07

40.00%

P2O5

0.22

0.14

-22.12%

0.21

-4.55%

K2O

4.86

3.7

-6.82%

7.23

48.77%

Na2O

2.94

1.01

-57.96%

2.11

-28.23%

TiO2

0.84

0.68

-0.92%

0.85

1.19%

SiO2

62.8

59.9

16.74%

58.7

-6.53%

LOI

1.4

2

74.84%

3.2

128.57%

Mass change

22.39%

0.00%

- 227 -

Average Least Altered Rhyodacite
0

Elements

Least altered Ci

Au (ppb)

4

Ag (ppm)

0.35

As

6.67

Ba

979

Be

Altered

96232
% Gain or Loss

Altered

96233
% Gain or Loss

Altered

96239
% Gain or Loss

Ci

ΔCi%

Ci

ΔCi%

Ci

ΔCi%

46

1262.96%

3

-20.53%

6

55.84%

0.1

-66.14%

0.05

-84.86%

0.9

167.16%

104

1747.96%

8

27.09%

19.4

202.19%

2420

192.97%

2060

122.96%

3000

218.37%

2.3

0.7

-63.93%

1.6

-26.29%

1.1

-50.31%

Bi

0.43

2.3

533.94%

0.2

-50.72%

0.6

44.97%

Cd

0.2

0.2

18.52%

0.3

58.94%

0.2

3.90%

Ce

93

19

-75.79%

90

2.54%

40

-55.31%

Co

6.2

47.9

815.65%

12.6

115.34%

7.7

29.03%

Cr

99.7

111

31.95%

171

81.74%

164

70.90%

Cs

2.1

1.4

-20.99%

1.3

-34.41%

1.4

-30.74%

Cu

18.23

68.3

344.04%

7.3

-57.57%

15.8

-9.95%

Dy

3.99

1.91

-43.27%

3.29

-12.63%

1.83

-52.35%

Er

2.12

1.28

-28.33%

1.87

-6.39%

0.95

-53.37%

Eu

1.35

1.19

4.47%

1.72

35.00%

1.82

40.07%

Ga

17.73

9.7

-35.17%

17.6

5.16%

13.5

-20.91%

Gd

4.53

1.7

-55.49%

4.46

4.40%

2.34

-46.29%

Ge

1.33

1

-11.11%

1.2

-4.64%

1.2

-6.49%

Hf

5.60

6.1

29.10%

6.3

19.21%

5.3

-1.67%

Hg

0.23

1.3

560.32%

0.3

36.23%

0.7

211.69%

Ho

0.95

0.52

-35.13%

0.82

-8.54%

0.44

-51.88%

La

49

11

-73.39%

51

10.29%

22

-53.35%

Lu

0.37

0.3

-3.03%

0.3

-13.31%

0.2

-43.33%

Mo

1.9

0.8

-50.10%

2.8

56.15%

1.3

-28.91%

Nb

9.7

9

9.97%

7

-23.53%

8

-14.31%

Nd

33.17

7.5

-73.20%

32.9

5.11%

15

-53.01%

Ni

19

5

-68.81%

4

-77.69%

3

-83.60%

Pb

21.13

9.27

-48.00%

8.99

-54.92%

12.2

-40.01%

Pr

10.14

2.26

-73.58%

10.4

8.68%

4.38

-55.12%

Rb

194

345

110.77%

282

54.02%

366

96.01%

Sb

1.3

9

720.51%

9

633.57%

11

779.12%

Sc
Se

7
0.67

3
0.5

-49.21%
-11.55%

11
2

66.51%
216.30%

7
1

3.90%
55.07%

Sm

5.26

1.51

-65.98%

5.31

6.97%

2.66

-47.46%

Sn

1.28

9.5

779.63%

7.2

496.03%

10.8

776.62%

Sr

206

72

-58.58%

87

-55.25%

67

-66.21%

Ta

1.6

1.74

28.89%

1.3

-13.91%

1.34

-12.99%

Tb

0.7

0.3

-49.21%

0.66

-0.09%

0.35

-48.05%

Te

0.05

0.4

848.15%

0.05

5.96%

0.05

3.90%

Th

22.03

25.9

39.34%

20.3

-2.36%

17.4

-17.94%

Tl

0.005

0.005

18.52%

0.005

5.96%

0.005

3.90%

Tm

0.39

0.25

-24.03%

0.32

-13.06%

0.16

-57.38%

U

5.98

5.75

13.96%

16.7

195.91%

3.81

-33.81%

V

38.3

20

-38.11%

83

129.63%

80

117.02%

W

24

126

522.22%

150

562.25%

194

739.83%

Y

23.1

13.6

-30.22%

21.2

-2.76%

11

-50.53%

Yb

2.33

1.71

-13.02%

1.88

-14.50%

1

-55.41%

Zn

46

2

-94.85%

0.5

-98.85%

6

-86.45%

Zr

195

172

4.54%

222

20.63%

188

0.17%

Al 2O3 (wt.%)

16

13.5

0.00%

15.1

0.00%

15.4

0.00%

CaO

2.49

0.11

-94.76%

0.16

-93.19%

0.22

-90.82%

Fe2O3

3.51

4.95

67.14%

7.11

114.64%

4.25

25.80%

MgO

1.15

0.22

-77.33%

0.29

-73.28%

0.25

-77.41%

MnO

0.07

0.005

-91.53%

0.005

-92.43%

0.01

-85.16%

P2O5

0.07

0.04

-32.28%

0.1

51.37%

0.12

78.11%

K2O

5.11

11.7

171.36%

11.4

136.39%

12.8

160.25%

Na2O

3

0.19

-92.49%

0.99

-65.03%

0.22

-92.38%

TiO2

0.43

0.32

-11.80%

0.62

52.78%

0.61

47.39%

SiO2

66.7

66.6

18.34%

63.3

0.56%

65.1

1.40%

LOI

1.5

2.3

81.73%

0.7

-50.55%

0.8

-44.59%

Mass change

18.52%

5.96%

- 228 -

3.90%

Average Least Altered Rhyodacite
0

Elements

Least altered Ci

96479

97080

97123

Altered

% Gain or Loss

Altered

% Gain or Loss

Altered

Ci

ΔCi%

Ci

ΔCi%

Ci

ΔCi%

% Gain or Loss

Au (ppb)

4

1

-72.41%

1

-74.84%

1

-69.70%

Ag (ppm)

0.35

0.6

89.16%

0.3

-13.75%

0.05

-82.68%

As

6.67

8.7

43.93%

2.5

-62.28%

2.4

-56.39%

Ba

979

2800

215.59%

978

0.53%

1130

39.91%

Be

2.3

1.4

-32.83%

3.6

57.51%

1.2

-36.76%

Bi

0.43

0.6

53.97%

0.4

-6.39%

0.2

-43.62%

Cd

0.2

0.1

-44.83%

0.1

-49.69%

0.05

-69.70%

Ce

93

119

41.19%

89

-3.70%

63

-17.89%

Co

6.2

5.3

-5.67%

6.4

3.88%

4.1

-19.84%

Cr

99.7

152

68.23%

92

-7.14%

157

90.88%

Cs

2.1

1.3

-31.69%

1.6

-23.33%

0.5

-71.14%

Cu

18.23

25

51.32%

67.4

272.05%

18.9

25.67%

Dy

3.99

3.36

-7.08%

3.92

-1.14%

3.46

5.11%

Er

2.12

1.88

-1.99%

2.12

0.79%

1.94

11.10%

Eu

1.35

1.98

61.84%

1.3

-3.10%

0.83

-25.48%

Ga

17.73

12.5

-22.22%

15.6

-11.48%

13.5

-7.72%

Gd

4.53

4.74

15.55%

4.42

-1.74%

3.12

-16.45%

Ge

1.33

1.2

-0.69%

1.2

-9.43%

1.2

9.09%

Hf

5.60

5.5

8.37%

6.6

18.60%

4.1

-11.26%

Hg

0.23

0.6

183.74%

0.05

-78.44%

0.05

-74.03%

Ho

0.95

0.8

-7.08%

0.91

-3.61%

0.79

0.80%

La

49

71

59.89%

45

-7.59%

32

-20.84%

Lu

0.37

0.4

20.38%

0.4

9.78%

0.3

-0.83%

Mo

1.9

2.4

39.38%

1.8

-4.67%

1.5

-4.31%

Nb

9.7

10

13.76%

10

3.74%

0.5

-93.75%

Nd

33.17

41.1

36.74%

32.4

-1.70%

20.2

-26.18%

Ni

19

4

-76.77%

6

-68.22%

6

-61.72%

Pb

21.13

10.5

-45.17%

16.8

-19.99%

5.81

-66.67%

Pr

10.14

12.9

40.38%

10.2

1.22%

6.4

-23.50%

Rb

194

389

121.26%

207

7.37%

176

9.97%

Sb

1.3

11

833.69%

2

54.81%

1

-6.76%

Sc
Se

7
0.67

4
0.5

-36.95%
-17.65%

7
0.5

0.63%
-24.90%

3
0.5

-48.05%
-9.54%

Sm

5.26

6.04

26.71%

5.45

4.26%

3.29

-24.18%

Sn

1.28

3.8

227.59%

3.5

175.16%

4.6

335.61%

Sr

206

123

-34.11%

166

-18.91%

27

-84.11%

Ta

1.6

1.61

11.03%

1.46

-8.18%

2.28

72.73%

Tb

0.7

0.68

7.19%

0.69

-0.81%

0.54

-6.49%

Te

0.05

0.05

10.34%

0.05

0.63%

0.05

21.21%

Th

22.03

24.3

21.71%

22.3

1.86%

32.9

81.02%

Tl

0.005

0.005

10.34%

0.005

0.63%

0.005

21.21%

Tm

0.39

0.34

-3.80%

0.38

-1.95%

0.33

2.56%

U

5.98

6.27

15.70%

6.82

14.76%

13.2

167.56%

V

38.3

29

-16.45%

35

-8.04%

13

-58.86%

W

24

68

212.64%

4

-83.23%

20

1.01%

Y

23.1

20.4

-2.55%

21.7

-5.47%

21.5

12.82%

Yb

2.33

2.24

6.08%

2.33

0.63%

2.08

8.21%

Zn

46

0.5

-98.80%

94

105.63%

0.5

-98.68%

Zr

195

178

0.73%

200

3.21%

109

-32.25%

Al 2O3 (wt.%)

16

14.5

0.00%

15.9

0.00%

13.2

0.00%

CaO

2.49

0.07

-96.90%

1.81

-26.85%

0.18

-91.24%

Fe2O3

3.51

4

25.75%

3.8

8.94%

2.14

-26.10%

MgO

1.15

0.3

-71.21%

1.2

5.00%

0.26

-72.60%

MnO

0.07

0.005

-92.12%

0.11

58.13%

0.01

-82.68%

P2O5

0.07

0.03

-52.71%

0.07

0.63%

0.005

-91.34%

K2O

5.11

11.5

148.33%

5.15

1.42%

6.58

56.08%

Na2O

3

0.18

-93.38%

2.86

-4.07%

3.23

30.51%

TiO2

0.43

0.35

-10.18%

0.43

0.63%

0.19

-46.44%

SiO2

66.7

68.2

12.83%

66.2

-0.13%

73.5

33.57%

LOI

1.5

0.6

-55.86%

1.5

0.63%

0.4

-67.68%

Mass change

10.34%

0.63%

- 229 -

21.21%

Average Least Altered Rhyodacite
0

Altered

97124
% Gain or Loss

Altered

97129
% Gain or Loss

Altered

97138
% Gain or Loss

Elements

Least altered Ci

Ci

ΔCi%

Ci

ΔCi%

Ci

ΔCi%

Au (ppb)

4

3

-20.00%

1

-72.03%

16

357.14%

Ag (ppm)

0.35

0.05

-84.76%

0.05

-84.02%

0.9

193.88%

As

6.67

11.3

80.71%

8.1

35.88%

24.9

326.64%

Ba

979

679

-26.02%

1450

65.72%

1030

20.24%

Be

2.3

1.3

-39.71%

1.1

-46.49%

2.3

14.29%

Bi

0.43

1.6

296.90%

0.1

-73.98%

1.7

351.83%

Cd

0.2

0.1

-46.67%

0.05

-72.03%

0.05

-71.43%

Ce

93

226

159.21%

111

33.54%

66

-18.89%

Co

6.2

29.6

409.25%

8.6

55.20%

48

784.79%

Cr

99.7

195

108.63%

145

62.73%

166

90.29%

Cs

2.1

0.4

-79.68%

0.4

-78.69%

0.4

-78.23%

Cu

18.23

113

561.18%

60.9

273.78%

1290

7987.14%

Dy

3.99

8.93

138.73%

3.15

-11.67%

3.68

5.41%

Er

2.12

4.37

120.22%

1.82

-3.79%

1.91

3.13%

Eu

1.35

2.39

88.84%

1.21

0.28%

0.8

-32.28%

Ga

17.73

18.6

11.88%

12.6

-20.50%

15.2

-2.04%

Gd

4.53

12.8

201.62%

3.85

-4.84%

3.4

-14.16%

Ge

1.33

2.1

68.00%

1

-16.08%

1.2

2.86%

Hf

5.60

5.5

4.76%

4.2

-16.08%

4.6

-6.12%

Hg

0.23

0.05

-77.14%

0.1

-52.05%

2

879.59%

Ho

0.95

1.9

113.33%

0.74

-12.85%

0.84

1.05%

La

49

119

159.05%

61

39.29%

36

-16.03%

Lu

0.37

0.7

103.64%

0.3

-8.46%

0.3

-6.49%

Mo

1.9

6.2

248.07%

4.9

188.55%

2.4

44.36%

Nb

9.7

0.5

-94.50%

0.5

-94.23%

0.5

-94.11%

Nd

33.17

95.2

206.17%

35.4

19.42%

22.7

-21.78%

Ni

19

11

-38.25%

6

-64.67%

27

62.41%

Pb

21.13

11

-44.47%

6.12

-67.59%

3.22

-82.58%

Pr

10.14

27.2

186.13%

11.5

26.89%

6.99

-21.22%

Rb

194

89.8

-50.63%

214

23.42%

186

9.57%

Sb

1.3

6

392.31%

2

72.14%

1

-12.09%

Sc
Se

7
0.67

9
1

37.14%
59.20%

5
0.5

-20.08%
-16.50%

5
0.5

-18.37%
-14.71%

Sm

5.26

17

244.74%

4.96

5.51%

3.59

-22.00%

Sn

1.28

8.8

633.33%

1.6

39.86%

5.3

373.21%

Sr

206

191

-1.10%

42

-77.19%

28

-84.47%

Ta

1.6

1.56

4.00%

1.76

23.08%

1.75

25.00%

Tb

0.7

1.73

163.62%

0.57

-8.89%

0.58

-5.31%

Te

0.05

0.3

540.00%

0.05

11.89%

0.4

814.29%

Th

22.03

20

-3.16%

25.6

30.02%

25.4

31.77%

Tl

0.005

0.005

6.67%

0.005

11.89%

0.005

14.29%

Tm

0.39

0.78

113.33%

0.33

-5.33%

0.34

-0.37%

U

5.98

11.6

106.91%

10.2

90.85%

10.7

104.49%

V

38.3

47

30.90%

28

-18.20%

37

10.41%

W

24

11

-51.11%

51

137.76%

560

2566.67%

Y

23.1

50

130.88%

19.8

-4.10%

20.4

0.93%

Yb

2.33

4.85

122.03%

2.2

5.65%

2.26

10.85%

Zn

46

26

-39.71%

6

-85.41%

2

-95.03%

Zr

195

178

-2.63%

122

-30.00%

139

-18.53%

Al 2O3 (wt.%)

16

15

0.00%

14.3

0.00%

14

0.00%

CaO

2.49

6.68

186.16%

0.41

-81.58%

0.39

-82.10%

Fe2O3

3.51

5.82

76.87%

2.76

-12.02%

5.6

82.34%

MgO

1.15

0.39

-63.83%

0.38

-63.03%

0.37

-63.23%

MnO

0.07

0.1

52.38%

0.02

-68.03%

0.01

-83.67%

P2O5

0.07

0.1

52.38%

0.03

-52.05%

0.05

-18.37%

K2O

5.11

3.45

-27.98%

8.5

86.12%

6.82

52.53%

Na2O

3

2.72

-3.29%

2.6

-3.03%

3.59

36.76%

TiO2

0.43

0.61

51.32%

0.29

-24.54%

0.3

-20.27%

SiO2

66.7

63.9

2.19%

70

17.42%

68

16.51%

LOI

1.5

1.4

-0.44%

0.5

-62.70%

0.7

-46.67%

Mass change

6.67%

11.89%

- 230 -

14.29%

Average Least Altered Rhyodacite
0

Altered

97143
% Gain or Loss

Elements

Least altered Ci

Ci

ΔCi%

Au (ppb)

4

11

205.56%

Ag (ppm)

0.35

0.05

-84.13%

As

6.67

34.2

469.72%

Ba

979

1070

21.44%

Be

2.3

1.8

-13.04%

Bi

0.43

0.3

-22.48%

Cd

0.2

0.1

-44.44%

Ce

93

118

40.98%

Co

6.2

20.2

262.01%

Cr

99.7

163

81.66%

Cs

2.1

0.4

-78.84%

Cu

18.23

106

546.07%

Dy

3.99

3.37

-6.15%

Er

2.12

2.01

5.51%

Eu

1.35

1

-17.70%

Ga

17.73

15

-6.02%

Gd

4.53

3.61

-11.39%

Ge

1.33

1.2

0.00%

Hf

5.60

4.7

-6.75%

Hg

0.23

0.05

-76.19%

Ho

0.95

0.83

-2.92%

La

49

65

47.39%

Lu

0.37

0.3

-9.09%

Mo

1.9

6.6

285.96%
-94.27%

Nb

9.7

0.5

Nd

33.17

37.5

25.63%

Ni

19

11

-35.67%

Pb

21.13

5.06

-73.39%

Pr

10.14

12.3

34.78%

Rb

194

146

-16.38%

Sb

1.3

3

156.41%

Sc

7

4

-36.51%

Se

0.67

0.5

-17.08%

Sm

5.26

4.94

4.35%

Sn

1.28

0.05

-95.66%

Sr

206

25

-86.52%

Ta

1.6

1.84

27.78%

Tb

0.7

0.57

-9.52%

Te

0.05

0.1

122.22%

Th

22.03

27

36.18%

Tl

0.005

0.005

11.11%

Tm

0.39

0.34

-3.13%

U

5.98

9.48

76.14%

V

38.3

31

-10.07%

W

24

8

-62.96%

Y

23.1

20.9

0.53%

Yb

2.33

2.12

1.10%

Zn

46

0.5

-98.79%

Zr

195

143

-18.52%

Al 2O3 (wt.%)

16

14.4

0.00%

CaO

2.49

0.42

-81.26%

Fe2O3

3.51

3.62

14.59%

MgO

1.15

0.25

-75.85%

MnO

0.07

0.01

-84.13%

P2O5

0.07

0.04

-36.51%

K2O

5.11

5.95

29.38%

Na2O

3

4.52

67.41%

TiO2

0.43

0.31

-19.90%

SiO2

66.7

69.7

16.11%

LOI

1.5

0.4

-70.37%

Mass change

11.11%
O

Abbreviations: Ci = concentration of compound/element I in least altered rock, C i = concentration of

- 231 -

Curriculum Vitae

Name:
Mark Hamilton

Post-secondary Education and Degrees:
Brandon University
Brandon, Manitoba, Canada
2016 M.Sc., Environment and Life Science
Brandon University
Brandon, Manitoba, Canada
2014 B.Sc., Geology
University of Manitoba
Winnipeg, Manitoba, Canada
2010 B.A. Physical Geography
Related Work Experience:
Laboratory Teacher & Teaching Assistant
Brandon University
2013 - 2016
Microanalytical Laboratory Assistant
Brandon University
2014 – 2015
Geologist Assistant
BFR Copper & Gold
2013 (summer program)
Geologist Assistant
Manitoba Geological Survey
2012 (summer program)

- 232 -