Texture and composition of scheelite, tourmaline and

rutile in orogenic gold deposits

Thesis

Marjorie SCIUBA

Doctorat interuniversitaire en Sciences de la Terre

Philosophiae Doctor (Ph.D.)

Sous la direction de :

Georges BEAUDOIN, directeur de recherche

Québec, Canada

© Marjorie Sciuba, 2020

ii

Résumé

La scheelite, la tourmaline et le rutile des gisements d’or orogénique, encaissés dans des roches de composition

et de faciès métamorphique variés ont été étudiés pour établir des paramètres discriminants pour contraindre

les campagnes utilisant les minéraux indicateurs pour l’exploration aurifère. La texture et les associations

minérales ont été investiguées par microscopie optique et microscopie électronique à balayage (MEB). La

scheelite, la tourmaline et le rutile présentent une grande variabilité de taille, de texture et d’association minérale,

qui ne sont pas informatives pour les campagnes de minéraux indicateurs. La composition minérale a été

déterminée par microsonde électronique (EPMA) et ablation laser et spectroscopie de masse avec plasma

couplée par induction (LA-ICP-MS). Les résultats ont été investigués par des diagrammes élémentaires et des

analyses multivariées incluant des analyses en composantes principales (PCA) et des analyses de réduction

des moindres carrées (PLS-DA). La composition et le faciès métamorphique des roches encaissantes

régionales exercent un fort contrôle sur la composition en éléments traces de la scheelite, de la tourmaline et

du rutile. Dans la scheelite, Sr, Pb, U, Th, Na, Éléments des Terres Rares (ETR) et Y; dans la tourmaline Ga et

Sn; et dans le rutile Nb, Ta, V et Cr varient avec la composition de la roche encaissante. Dans la scheelite, ETR,

Y, Sr, Mn, Nb, Ta et V; dans la tourmaline, Ga, Sn, Ti, ETR, Zr, Hf, Nb, Ta, Th et U; et dans le rutile Nb, Ta, V

et Cr varient avec le faciès métamorphique des roches encaissantes. La composition en éléments traces de la

scheelite varie avec l’âge de la roche encaissante alors que la tourmaline et le rutile ne montrent pas de variation

compositionnelle avec l’âge de l’encaissant. La variation compositionnelle résulte des échanges fluide-roche

lors de la circulation du fluide hydrothermal jusqu’au site de dépôt de l’or. Les résultats pour les minéraux des

gisements d’or orogénique sont comparés avec ceux d’autres types de gîtes et de paramètres géologiques

variées de la littérature. La scheelite et la tourmaline des gisements d’or orogénique présentent clairement une

variation compositionnelle distincte comparée à celle d’autres types de gîtes et paramètres géologiques. La

scheelite des gisements d’or orogénique a une signature distincte en Sr, Mo, Eu, As et Sr/Mo mais similaire en

ETR par rapport à la scheelite provenant d’autres types de gîtes. Les diagrammes binaires tels que Sr/Li vs

V/Sn, Sr/Sn vs V/Nb, Sr/Sn vs Ni/Nb et Sr/Sn vs V/Be discriminent la tourmaline des gisements d’or orogénique

de celle provenant d’autres sources. Les diagrammes élémentaires mettent en avant une variation

transitionnelle de la composition en éléments traces de la tourmaline provenant d’environnement

métamorphique, à hydrothermal-magmatique, à magmatique. Le rutile des gisements d’or orogénique a une

composition distincte en Mn, V, Sn, Sb et W comparée aux rutiles provenant d’autres types de gîtes et

paramètres géologiques. Les diagrammes binaires incluant V vs Sb et Nb/V vs. Sn/V discriminent le rutile des

gisements d’or orogénique et celui provenant des environnements magmatique-hydrothermaux et

magmatiques. D’autres diagrammes binaires tel que Nb/V vs W permettent de distinguer partiellement le rutile

iii

des gisements d’or orogénique et celui provenant d’environnement hydrothermaux et métamorphique-

hydrothermaux.

iv

Abstract

Scheelite, tourmaline and rutile from orogenic gold deposits and districts, hosted in varied country rocks and

metamorphic facies of various ages were investigated to establish discriminant features to constrain indicator

mineral surveys for gold exploration. Texture and mineral associations were investigated by optical microscopy

and Scanning Electron Microscopy (SEM). Scheelite, tourmaline and rutile present a wide range of size, texture,

and mineral association that are not informative for indicator mineral surveys. Mineral composition was

determined using Electron Probe Micro-Analyzer (EPMA) and Laser Ablation-Inductively Coupled Plasma-Mass

Spectrometry (LA-ICP-MS). Results were investigated with elemental plots and multivariate statistics including

Principal Component Analysis (PCA) and Partial Least Square-Discriminant Analysis (PLS-DA). The

composition of the metamorphic facies of the local country rocks as well as the regional country rocks exert a

strong control on scheelite, tourmaline and rutile trace element composition. In scheelite Sr, Pb, U, Th, Na, REE

and Y; in tourmaline Ga and Sn; and in rutile Nb, Ta, V and Cr vary with the country rock composition. In

scheelite, REE, Y, Sr, Mn, Nb, Ta and V; in tourmaline, Ga, Sn, Ti, REE, Zr, Hf, Nb, Ta, Th and U; and in rutile

Nb, Ta, V and Cr vary with the metamorphic facies of the country rocks. Scheelite trace element composition

vary with the country rock age whereas tourmaline and rutile do not show any compositional variation with the

country rock age. Compositional variation results of fluid-rock exchange during fluid flow to gold deposition site.

Results for minerals from orogenic gold deposits are compared with those from various deposit types and

geological settings from literature. Scheelite and tourmaline from orogenic gold deposits present clearly a distinct

compositional variation, compared to scheelite and tourmaline from other deposit types and geological settings.

Scheelite from orogenic gold deposits have distinct Sr, Mo, Eu, As and Sr/Mo, but indistinguishable REE

signatures, compared to scheelite from other deposit types. Binary plots such as Sr/Li vs V/Sn, Sr/Sn vs V/Nb,

Sr/Sn vs Ni/Nb and Sr/Sn vs V/Be discriminate orogenic gold deposit tourmaline from that from other sources.

Elemental plots highlight a transitional variation in the trace element composition of tourmaline from

metamorphic, to hydrothermal-magmatic to, magmatic environments. Rutile from orogenic gold deposits has a

distinctive Mn, V, Sn, Sb and W composition compared to those from various deposits types and geological

settings. Binary diagrams, including V vs Sb and Nb/V vs Sn/V, discriminate rutile from orogenic gold deposits

from those from hydrothermal-magmatic and magmatic deposit types. Other binary diagrams, such as Nb/V vs

W, discriminate partially orogenic gold deposit rutile from hydrothermal and metamorphic-hydrothermal

environments.

v

Table of content

Résumé ............................................................................................................................................................... ii

Abstract ............................................................................................................................................................... iv

Table of content ................................................................................................................................................... v

List of figures .................................................................................................................................................... viii

List of tables ...................................................................................................................................................... xiii

List of appendices ............................................................................................................................................. xiv

Acknowledgements ........................................................................................................................................... xix

Foreword ............................................................................................................................................................ xx

Introduction ......................................................................................................................................................... 1

Chapter 1. Trace element composition of scheelite in orogenic gold deposits ............................................... 4

1.1. Résumé ............................................................................................................................................. 4

1.2. Abstract ............................................................................................................................................. 4

1.3. Introduction ........................................................................................................................................ 5

1.4. Geological settings of the selected orogenic gold deposits ............................................................... 6

1.5. Scheelite texture and mineral assemblages ...................................................................................... 7

1.6. Analytical methods ............................................................................................................................ 9

1.6.1. Sample preparation ................................................................................................................... 9

1.6.2. Electron Probe Micro-Analysis (EPMA) ..................................................................................... 9

1.6.3. Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) ......................... 9

1.6.4. Statistical analysis ................................................................................................................... 10

1.7. Results ............................................................................................................................................ 11

1.7.1. Cathodoluminescence and trace elements variation ............................................................... 11

1.7.2. Trace element composition ...................................................................................................... 11

1.7.3. Multivariate statistics of scheelite trace element composition .................................................. 22

1.8. Discussion ....................................................................................................................................... 25

vi

1.8.1. Trace element substitution ....................................................................................................... 25

1.8.2. REE patterns ........................................................................................................................... 27

1.8.3. Comparison to scheelite from other types of deposits ............................................................. 29

1.9. Conclusions ..................................................................................................................................... 32

Chapter 2. Chemical composition of tourmaline in orogenic gold deposits ................................................... 34

2.1. Résumé ........................................................................................................................................... 34

2.2. Abstract ........................................................................................................................................... 34

2.3. Introduction ...................................................................................................................................... 35

2.4. Geological setting of the selected orogenic gold deposits ............................................................... 36

2.5. Analytical methods .......................................................................................................................... 37

2.5.1. Sample selection and preparation ........................................................................................... 37

2.5.2. Electron Probe Micro-Analysis (EPMA) ................................................................................... 37

2.5.3. Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) ....................... 38

2.5.4. Multivariate statistical analysis ................................................................................................. 38

2.6. Results ............................................................................................................................................ 38

2.6.1. Tourmaline textures and mineral assemblages ....................................................................... 38

2.6.2. Major element composition ...................................................................................................... 41

2.6.3. Minor and trace element composition ...................................................................................... 42

2.6.4. Chemical zoning ...................................................................................................................... 46

2.6.5. Multi-variate analysis of tourmaline composition in relation to the geological environment ..... 46

2.7. Discussion ....................................................................................................................................... 49

2.7.1. Influence of geological settings ................................................................................................ 49

2.7.2. Rare Earth Elements patterns ................................................................................................. 50

2.7.3. Comparison to tourmaline from various deposit types and geological environments .............. 51

2.8. Conclusions ..................................................................................................................................... 55

Chapter 3. Texture and trace element composition of rutile in orogenic gold deposits ................................. 56

3.1. Résumé ........................................................................................................................................... 56

3.2. Abstract ........................................................................................................................................... 56

3.3. Introduction ...................................................................................................................................... 57

3.4. Physical and chemical properties of rutile ....................................................................................... 58

3.4.1. Trace element composition of TiO2 polymorphs ...................................................................... 59

3.5. Geological settings of the selected orogenic gold deposits ............................................................. 59

vii

3.6. Analytical method ............................................................................................................................ 59

3.6.1. Sample preparation ................................................................................................................. 59

3.6.2. Scanning Electron Microscopy (SEM) ..................................................................................... 60

3.6.3. Electron Probe Micro-Analysis (EPMA) ................................................................................... 60

3.6.4. Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) ....................... 60

3.6.5. Statistical analysis ................................................................................................................... 61

3.7. Rutile texture and mineral assemblages ......................................................................................... 61

3.8. Results ............................................................................................................................................ 63

3.8.1. Chemical zoning ...................................................................................................................... 63

3.8.2. TiO2 polymorphs ...................................................................................................................... 64

3.8.3. Compositional variations in relation to the geological settings ................................................. 66

3.8.4. Multivariate statistical analysis of rutile trace element composition ......................................... 69

3.9. Discussion ....................................................................................................................................... 74

3.9.1. Rutile grain size ....................................................................................................................... 74

3.9.2. Assimilation of the country rock signature ............................................................................... 75

3.9.3. Comparison to rutile from various deposit types and geological environments ....................... 77

3.10. Conclusions ..................................................................................................................................... 79

Conclusions ...................................................................................................................................................... 80

Bibliography ...................................................................................................................................................... 82

Appendices ..................................................................................................................................................... 107

viii

List of figures

Figure 0-1. Distribution of the selected orogenic gold deposits in this study, (a) in the world Map is adapted from

the Canada Geological Survey database; (b) in the Abitibi subprovince, Canada; map modified from

Poulsen et al. (2000) and (c) in the Yilgarn craton, Australia. Map is adapted from Robert et al. (2005).

.............................................................................................................................................................. 4

Figure 1-1. Scheelite texture and mineral associations in orogenic gold deposits (a) aggregate of anhedral

scheelite grains (Cuiaba, Brazil), (b) subhedral scheelite grains (Canadian Malartic, Abitibi), (c) dynamic

recrystallization of scheelite at Hutti (India), (d) fine grains disseminated scheelite (Kochkar, Russia),

(e) scheelite veins (Kumtor, Kyrgyzstan), (f) scheelite associated with hydrothermal and metamorphic

minerals such as clinopyroxene (Navachab, Namibia), (g) scheelite in association with tourmaline

(Essakane, Burkina Faso), (h) scheelite is associated with pyrite with gold inclusion at Tarmoola,

Eastern Goldfields, (i) scheelite with native gold, magnetite and hematite (Crusader, Australia). ........ 8

Figure 1-2. Cathodoluminescence (CL) images of scheelite show (a) homogeneous CL (Dome, Abitibi; the halo

effect is an artefact due to camera resolution), (b) sub-grains within larger scheelite (Essakane, Burkina

Faso), (c) homogeneous fine grains (Hutti, India), (d) homogenous scheelite cut by thin veinlets

(Tarmoola, Yilgarn), (e) brecciated (Mount Pleasant, Southern Cross), (f) brecciated structure at the

edge of the grain (Crusader, Australia), (g) oscillatory zoning (Kochkar, Russia), (h) homogeneous CL

(Rosebel, Suriname), (i) oscillatory zoning (Crusader, Agnew district). .............................................. 12

Figure 1-3. Variation of the trace elements composition with the CL zonation in scheelite from the Macraes

deposit, New Zealand. (a) The CL shows two generations: the first generation labelled “1” is brecciated

by the second generation labelled “2”. (b) LA-ICP-MS profile shows the trace element variation within

the different scheelite generations. The first generation is characterized by high Sr, Na, Mg, Mn, Th and

U, and low Y and ∑REE content, whereas, the second generation is characterized by low Sr, Na, Mg,

Mn, Th and U, and high Y and ∑REE content. Zones 2a and 1b are too small to be quantified. (c) The

first generation is characterized by a flat REE pattern and the second generation is characterized by a

bell-shaped REE pattern, both with positive Eu anomalies. ................................................................ 13

Figure 1-4. Images of scheelite (a) reflected light, (b) cathodoluminescence and trace elements LA-ICP-MS

maps in (c) Sr, (d) Mo, (e) Na, (f) Y, (g) Nb, (h) As, (i) Eu, (j) Gd and (k) Pb, show homogeneous

composition typical for scheelite from orogenic gold deposits (Dome, Abitibi).................................... 14

Figure 1-5. Rare earth element patterns in scheelite from orogenic gold deposits. (a) bell-shaped pattern with

positive Eu anomaly, (b) flat pattern with positive Eu anomaly, (c) bell-shaped with negative Eu

anomaly, (d) LREE-enriched pattern, (e) HREE-enriched pattern, (f) flat pattern without Eu anomaly.

Data are normalized to chondrite from McDonough and Sun (1995). The North American Shale

Composite (NASC) values are from Gromet et al. (1984). .................................................................. 15

Figure 1-6. Binary plots for REE contents in scheelite (a) (Gd/Yb)CN vs (La/Sm)CN and (b) ∑REE vs Eu* from

orogenic gold deposits, (c) (Gd/Yb)CN vs (La/Sm)CN and (d) ∑REE vs Eu* from various deposit types.

Data for orogenic gold deposits from literature include Ghaderi et al. (1999); Brugger et al. (2000b);

Roberts et al. (2006); Xiong et al. (2006); Liu Yan et al. (2007); Dostal et al. (2009); Song et al. (2014);

Cave et al. (2016); Hazarika et al. (2016); Poulin (2016). Abbreviations: Bell + : bell-shaped pattern with

positive Eu anomaly; Bell -: bell-shaped pattern with negative Eu anomaly; Bell Ho + : bell-shaped

ix

pattern centered in Ho with positive Eu anomaly as described in Dostal et al. (2009); Bell Ho - : bell-

shaped pattern centered in Ho with negative Eu anomaly as described in Dostal et al. (2009). ........ 17

Figure 1-7. LA-ICP-MS trace element binary plots for scheelite from orogenic gold deposits (a) ∑REE+Y vs Na;

(b) Eu anomaly (Eu*) vs Na; (c) Nb vs Ta; (d) ∑REE+Y vs Sr; (e) Na vs Sr, data for Rosebel are from

EPMA; (f) Pb vs Sr; (g) ∑REE+Y vs Nb+Ta+V; (h) ∑REE vs Y; (i) U vs Th. Data from the literature

include Ghaderi et al. (1999) and Dostal et al. (2009). ....................................................................... 19

Figure 1-8. Scheelite composition from orogenic gold and other deposit types for (a) Sr, (b) Mo, (c) Y and (d)

Na. Literature data for orogenic gold deposits are from Anglin et al. (1996); Ghaderi et al. (1999);

Brugger et al. (2000b); Dostal et al. (2009); Graupner et al. (2010); Hazarika et al. (2016); Poulin 2016;

Poulin et al. (2016). Data for skarn deposits are from Eichhorn et al. (1997); Zhigang et al. (1998); Liu

Yan et al. (2007); Peng et al. (2010); Song et al. (2014); Poulin (2016); Poulin et al. (2016). Data for

Greisen and VMS are from Poulin (2016). Abbreviation: Can. Malartic: Canadian Malartic. .............. 20

Figure 1-9. LA-ICP-MS trace element diagrams for scheelite in orogenic gold deposits (a)

(Sr+Na)/(Sr+Na+10x(Nb+Ta+V+As)) vs (REE+Y+10x(Nb+Ta+V+As))/

(Sr+REE+Y+10x(Nb+Ta+V+As)); (b) Fe-Mn-Mg scheelite composition measured by LA-ICP-MS; (c)

Fe-Mn-Mg carbonate composition. ..................................................................................................... 21

Figure 1-10. Partial Least Square-Discriminant Analysis of LA-ICP-MS data for scheelite in orogenic gold

deposits. (a) qw*1-qw*2 and (b) t1-t2 scores for mineralization age; (c) qw1*-qw2* and (d) t1-t2 scores for

host rock compositions; (e) qw*1-qw*2 and (f) t1-t2 scores for metamorphic facies of the host rocks. The

qw*1-qw*2 plots show the correlation between elements and the element contribution to each group.

The t1-t2 plots show the distribution of scheelite sample according to each preselected grouping. ... 24

Figure 1-11. LA-ICP-MS trace element binary plots for scheelite from orogenic gold deposits and other deposits

types (a) Sr vs Eu anomaly (Eu*), (b) Sr/Mo vs Eu*, (c) Mo vs As, and (d) Sr/Mo vs As. Data for orogenic

gold deposits: Ghaderi et al. (1999); Dostal et al. (2009); Cave et al. (2016); Hazarika et al. (2016);

Poulin (2016). Data for skarn deposits: Xiong et al. (2006); Ren et al. (2010); Song et al. (2014); Guo

et al. (2016); Poulin (2016); Fu et al. (2017), and for porphyry-related deposits: Poulin (2016) and Sun

and Chen (2017). ................................................................................................................................ 30

Figure 1-12. Partial Least Square-Discriminant Analysis of LA-ICP-MS data for scheelite from different deposit

types. (a) The qw*1-qw*2 loadings plot shows correlations among elemental variables and deposit types.

(b) The t1-t2 scores plot shows the distribution of scheelite samples in the qw*1-qw*2 space. (c) Variable

importance of the projection (VIP) per deposit types shows the detailed element contribution per

deposit. Data for orogenic gold deposits: Ghaderi et al. (1999); Dostal et al. (2009); Hazarika et al.

(2016) and Poulin (2016), for skarn deposits: Song et al. (2014) and Poulin (2016) and for porphyry-

related deposits: Poulin (2016) and Sun and Chen (2017). ................................................................ 32

Figure 2-1. Tourmaline textures and mineral associations in orogenic gold deposits (a) disseminated euhedral

greenish tourmaline (Royal Hill, Rosebel, Suriname), (b) disseminated euhedral tourmaline with light

blue core and subtle orange rim (Hoyle Pond, Canada), (c) aggregate of subhedral orange tourmaline

(Roberto, Canada), (d) aggregate of subhedral tourmaline with bluish grey core and greenish brown

rim (Canadian Malartic, Canada), (e) disseminated subhedral tourmaline with greyish core and

brownish rim associated with sulfides (New Consort, South Africa), (f) aggregate of subhedral orange

to brown tourmaline associated with gold (Essakane, Burkina Faso). ................................................ 40

x

Figure 2-2. Back-scattered electron images of tourmaline zoning in orogenic gold deposits, (a) Complex sector

zoning (Essakane, Burkina Faso), (b) oscillatory zoning coupled with sector zoning (Salsigne, France),

(c) oscillatory zoning (TR98-111, James Bay, Canada), (d) irregular zoning (Big Bell, Australia), (e)

narrow rim with large core (New Consort, South Africa), (f) thick rim with small core (Orezone, James

Bay, Canada). ..................................................................................................................................... 40

Figure 2-3. (a) Major, minor and (b) trace elements concentrations sorted by median tourmaline composition for

orogenic gold deposits, measured by EPMA and LA-ICP-MS. See Appendices C-5 and C-6 for EPMA

and LA-ICP-MS data. .......................................................................................................................... 41

Figure 2-4. (a) Back-scattered electron images of zoned tourmaline and EPMA maps, (b) Ti, (c) Fe, (d) Ca, (e)

Mg, (f) V (TR98-111 showing, James Bay, Canada). ......................................................................... 42

Figure 2-5. Classification of tourmaline from orogenic gold deposits and other deposit types and settings (a) X-

Vacant-Ca-(Na+K) ternary diagram (b) Mg/(Fe+Mg) vs Vac/(Na+K+Vac) diagram and (c) Mg/(Fe+Mg)

vs Ca/(Ca+Na) diagram. Diagrams are adapted from Henry et al. (2011). ......................................... 42

Figure 2-6. LA-ICP-MS trace element binary plots for tourmaline from orogenic gold deposits (a) La vs Zr, (b)

Yb vs Zr, (c) ∑REE vs Zr, (d) Zr vs Hf, (e) Fe vs Sn, (f) ∑REE vs Ti, (g) Eu anomaly vs Y, (h) Ni vs Co

and, (i) ∑REE vs Ga. Data from literature: Lottermoser and Plimer 1987; Slack and Coad 1989;

Gallagher and Kennan 1992; Jiang et al. (2002); Deksissa and Koeberl (2004); Roberts et al. (2006);

Hazarika et al. (2015); Hazarika et al. (2016); Grzela (2017); Kalliomäki et al. (2017); Manéglia (2017).

............................................................................................................................................................ 44

Figure 2-7. Rare earth element patterns in tourmaline from orogenic gold deposits. Data are normalized to

chondrite from McDonough and Sun (1995). Deposit patterns in Appendix C-15 .............................. 45

Figure 2-8. LA-ICP-MS binary plots of Eu anomaly vs (La/Sm)CN for tourmaline from (a) various deposit types

and (b) orogenic gold deposits only. Data from literature: Lottermoser and Plimer 1987; Slack and Coad

1989; Gallagher and Kennan 1992; Jiang et al. (2002); Deksissa and Koeberl (2004); Roberts et al.

(2006); Hazarika et al. (2015); Hazarika et al. (2016); Grzela (2017); Kalliomäki et al. (2017); Manéglia

(2017). ................................................................................................................................................ 45

Figure 2-9. Partial Least Square Discriminant Analysis of LA-ICP-MS data for tourmaline in orogenic gold

deposits hosted in country rock with various compositions. (a) qw*1-qw*2 loadings show correlations

among elemental variables and country rock classes, (b) t1-t2 scores shows the distribution of

tourmaline from in the space defined by qw*1-qw*2, and, (c) VIP shows the importance of compositional

variables in classification of different country rock classes. Data for orogenic gold deposits include

Grzela (2017) and Manéglia (2017). ................................................................................................... 47

Figure 2-10. Partial Least Square Discriminant Analysis of LA-ICP-MS data for tourmaline from orogenic gold

deposits hosted in country rocks with various compositions and metamorphosed to various facies. (a)

qw*1-qw*2 loadings show correlations among elemental variables and classes defined by composition

and metamorphic facies of the country rocks, (b) t1-t2 scores shows the distribution of tourmaline from

in the space defined by qw*1-qw*2, and (c) VIP shows the importance of compositional variables in

classification of classes defined by composition and metamorphic facies of the country rocks. Data for

orogenic gold deposits include Grzela (2017) and Manéglia (2017). .................................................. 48

Figure 2-11. Trace element binary plots for tourmaline from various deposit types and rocks (a) Sr vs V, (b) Nb

vs V, (c) Li vs Sn, (d) Ta vs Be, (e) Sr/Li vs V/Sn, (f) Sr/Sn vs V/Nb, (g) Ta vs Ni, (h) Nb vs Ga and, (i)

xi

Sr/Sn vs Ba. Data for orogenic gold deposits: Jiang et al. (2002); Deksissa and Koeberl (2004); Roberts

et al. (2006); Hazarika et al. (2015); Hazarika et al. (2016); Grzela (2017); Kalliomäki et al. (2017);

Manéglia (2017). ................................................................................................................................. 52

Figure 2-12. PLS-DA of LA-ICP-MS data for tourmaline from various deposit types and rocks using Li, Sc, V,

Co, Zn, Sr, Sn, and Pb (a) qw*1-qw*2 loadings loadings show correlations among elemental variables

and classes defined by deposit types and geological environments, (b) t1-t2 scores scores shows the

distribution of tourmaline from in the space defined by qw*1-qw*2, and (c) VIP shows the importance of

compositional variables in classification of classes defined by deposit types and geological

environments. ..................................................................................................................................... 54

Figure 3-1. BSE image of textures and zoning of rutile from orogenic gold deposits. (a) complex rutile with

lamellar zones with different shades of grey in contact with porous dark rutile (Hoyle Pond); (b) dark

grey rutile is replaced by light grey rutile or possibly sector zoning (Dome); (c) homogeneous, coarse

anhedral rutile with pyrite and quartz as possible late infilling in pyrite (Goldex); (d) anhedral rutile cut

by quartz-pyrite-carbonate vein (Obuasi); (e) homogeneous platy rutile in quartz vein, (Beaufor); (f)

rutile replaced by rim of titanite (Roberto); (g) anhedral rutile with complex zoning with possibly two

generations of rutile (Hoyle Pond); (h) rutile in inclusions in pyrite, dark grey rutile light grey rutile as

replacement texture or sector zoning (Muruntau) and (i) coarse grained rutile with thin lighter rutile

veinlets, cut by irregular veins of chlorite-quartz (Canadian Malartic). ................................................ 62

Figure 3-2. BSE images of textures and zoning of rutile from orogenic gold deposits. (a) anhedral rutile along

foliation around arsenopyrite possibly reflecting dissolution-precipitatioin textures (Juneau); (b)

anhedral rutile with pyrrhotite inclusions (New Consort); (c) pseudomorphic replacement of rutile grain

with cleavage (Tiriganiaq, Meliadine); (d) rutile inclusions in ilmenite (Rosebel); (e) and (f) anhedral

rutile with acicular inclusions of light grey rutile (Goldex); (g) rutile replacing ilmenite (St. Ives); (h) fine

grained acicular rutile replacing compositional bands of earlier ilmenite exsolutions (Hira Buddini) and

(i) rutile with treilli texture replacing ilmenite (Giant). .......................................................................... 63

Figure 3-3. Sector zoning in rutile (Muruntau) (a) under BSE, and trace elements EPMA maps in (b) Si, (c) Mg,

(d) Fe, (e) Mn, (f) Sn, (g) W, (h) Cr and, (i) Nb.................................................................................... 64

Figure 3-4. Irregular patchy zoning in rutile (Canadian Malartic) (a) transmitted light, and trace elements LA-ICP-

MS maps in (b) V, (c) Fe, (d) Sc, (e) Sb, (f) Sn, (g) W, (h) Nb, and (i) Ta. .......................................... 65

Figure 3-5. Ternary diagrams showing the trace element composition of TiO2 polymorphs: (a) Ti vs.

100(Fe+Cr+V) vs. 1000xW, adapted from Clark and Williams-Jones (2004). (b) Al+Ti/V vs.

Fe+Cr+Sb+Mo+Sn vs. 10x(W+Zr) adapted from Plavsa et al. (2018). (c) 100xCr vs. Al vs. Fe adapted

from Plavsa et al. (2018). (a) EPMA, (b) and (c) LA-ICP-MS data. ..................................................... 65

Figure 3-6. Trace element concentrations sorted by median for rutile from orogenic gold deposits, measured by

EPMA and LA-ICP-MS. See Appendix E-4 and Appendix E-6 for EPMA and LA-ICP-MS data,

respectively. ........................................................................................................................................ 66

Figure 3-7. Binary plots for rutile from orogenic gold deposits of (a) V vs. Nb, (b) Ta vs. Nb, (c) La vs. Ba, (d) U

vs. Th, (e) Y vs. Th, (f) La vs. Ca, (g) U/La vs. Zr/Th and (h) Zr/Ba vs. Sc/Y. (a) and (b) are with EPMA

data and (c) to (h) are with LA-ICP-MS data. Data from literature: Clark and Williams-Jones (2004);

Scott and Radford (2007); Dostal et al. (2009); Scott et al. (2011); Martin (2012); Auger (2016); Pochon

et al. (2017); Agangi et al. (2019). ...................................................................................................... 67

xii

Figure 3-8. Rare earth element patterns for rutile from orogenic gold deposits. Data are normalized to chondrite

from McDonough and Sun (1995). Deposit patterns in Appendix E-10. ............................................. 69

Figure 3-9. Partial Least Square-Discriminant Analysis of EPMA data for rutile from orogenic gold deposits

hosted in various country rocks. (a) qw*1-qw*2 loadings, (b) t1-t2 scores, (c) VIP-cumulative and scores

contributions for each group including rutile from deposits hosted in (d) felsic rocks, (e) intermediate

rocks, (f) mafic, (g) mafic-ultramafic and (h) sedimentary rocks VIP. Oblique lines in d and g show the

extend of the score contributions. Data from this study and Auger (2016). ........................................ 71

Figure 3-10. Partial Least Square-Discriminant Analysis of EPMA data for rutile from orogenic gold deposits

classified by country rocks metamorphosed to various facies. (a) qw*2-qw*3 loadings, (b) t2-t3 scores,

(c) VIP-cumulative and scores contributions for each group including rutile from deposits hosted in rocks

metamorphosed (d) from lower to middle greenschist facies, (e) in upper greenschist facies and (f) from

lower to middle amphibolite facies. Oblique lines in D and G show the extend of the score contributions.

Data from this study and Auger (2016). .............................................................................................. 73

Figure 3-11. Partial Least Square-Discriminant Analysis of LA-ICP-MS data for rutile from orogenic gold deposits

hosted in country rocks with various compositions and metamorphosed to various facies. (a) qw*1-qw*3

loadings and (b) t1-t3 scores and (c) VIP-cumulative. .......................................................................... 74

Figure 3-12. Trace element binary plots for rutile from various deposit types and rocks (a) V vs Mn, (b) V vs Sn,

(c) Fe vs n, (d) V vs Nb, (e) Nb vs U, (f) Fe vs Mn, (g) V vs Sb, (h) Nb/V vs W and (i) Nb/Sb vs Sn/V.

Plots (a), (e) and (f) refer to the LA-ICP-MS data and (b), (c), (d), (g) and (h) refers to the EPMA data.

............................................................................................................................................................ 78

xiii

List of tables

Table 2-1. Median trace element compositions in tourmaline from orogenic gold deposits with the metamorphic

facies of the country rock. ................................................................................................................... 46

Table 3-1. Median composition in rutile from deposits hosted in various metamorphic facies country rocks ... 68

xiv

List of appendices

Appendix A-1. Geological settings of the gold deposits studied for scheelite. ................................................ 108

Appendix A-2. Scheelite characteristics in the studied orogenic gold deposits ............................................... 112

Appendix A-3. Analytical conditions for trace element analyses in scheelite by EPMA. ................................. 115

Appendix A-4. EPMA elements composition in scheelite from orogenic gold deposits ................................... 116

Appendix A-5. Analytical conditions for trace element analyses in scheelite by LA-ICP-MS .......................... 120

Appendix A-6. LA-ICP-MS trace elements composition in scheelite from orogenic gold deposits .................. 121

Appendix A-7. Comparison between LA-ICP-MS and EPMA analyses for (a) Sr, (b) Mo, (c) Y and (d) Na. Red

line – 1:1 ratio; abbreviation: DL: Detection limit of the electron microprobe. ................................... 145

Appendix A-8. Trace elements concentrations sorted by median scheelite composition for orogenic gold

deposits, measured by LA-ICP-MS. .................................................................................................. 146

Appendix A-9. Carbonate coloration of samples with scheelite for deposits hosted in (a) low grade metamorphic

facies rocks (b) moderate grade metamorphic facies rocks (c) high grade metamorphic facies rocks.

.......................................................................................................................................................... 147

Appendix A-10. Variation of the trace elements composition with a the oscillatory zoning shown by CL in scheelite

from the Crusader deposit, Agnew district (Australia). Zone 1 is characterized by (a) darker CL and high

content in Na, V, As, Nb, Ta, Y and REE, and low Mo in (b). Zone 2 is brighter CL and low content in

Na, V, As, Nb, Ta, Y and REE, and higher Mo. (c) Both zones have a similar positive-slope REE pattern.

.......................................................................................................................................................... 148

Appendix A-11. Rare earth elements patterns from LA-ICP-MS data in scheelite from (a) Dome and Hollinger

(Timmins, Canada); (b) Young Davidson (Matachewan, Canada); (c) Malartic (Canada), (d) Val-d’Or

camp (Canada); (e) Meliadine (Canada); (f) Cuiaba (Brazil); (g) Buzwagi (Tanzania) and Essakane

(Burkina Faso), (h) Hutti (India); (i) Kochkar (Russia); (j) Kumtor (Kyrgyzstan). ............................... 149

Appendix A-12. Rare earth elements patterns from LA-ICP-MS data in scheelite from (a) Marvel Loch (Australia);

(b) Nevoria (Australia); (c) Edward’s Find (Australia); (d) Crusader (Australia); (e) Tarmoola (Australia);

(f) Paddington (Australia); (g) Mt Pleasant (Australia); (h) Norseman camp (Australia); (i) Mt. Charlotte

(Australia); (j) Macraes (New Zealand). ............................................................................................ 150

Appendix A-13. Principal Component Analysis of LA-ICP-MS data for scheelite in orogenic gold deposits. Rare

Earth Elements are reduced to ∑REE and Eu anomaly (Eu*). (a) PC1-PC2, (b) PC1-PC3 and (c) PC2-

PC3 with emphasis on the mineralization age, (d) PC1-PC2, (e) PC1-PC3 and (f) PC2-PC3 with

emphasis on the host rock composition, (g) PC1-PC2, (h) PC1-PC3 and (i) PC2-PC3 with emphasis on

the metamorphic facies of the host rock. .......................................................................................... 151

Appendix A-14. Principal Component Analysis of LA-ICP-MS data for scheelite from different deposit types. Data

from the literature for orogenic gold deposits: Dostal et al. (2009); Hazarika et al. (2016) and Poulin

(2016), for skarn deposits: Song et al. (2014) and Poulin (2016), and for porphyry related deposits:

Poulin (2016) and Sun and Chen (2017). ......................................................................................... 152

xv

Appendix B-1. Images of scheelite (a) reflected light, (b) cathodoluminescence and trace elements LA-ICP-MS

maps in (c) As, (d) Sr, (e) Mo, (f) Nb, (g) Sr, (h) V, (i) La, (j) Y and (k) Eu (thin section MALA-10,

Canadian Malartic, Canada). ............................................................................................................ 153

Appendix B-2. Images of scheelite (a) reflected light, (b) cathodoluminescence and trace elements LA-ICP-MS

maps in (c) As, (d) Sr, (e) Mo, (f) Nb, (g) Sr, (h) V, (i) La, (j) Y and (k) Eu (thin section CUIA-03, Cuiaba,

Brazil). ............................................................................................................................................... 154

Appendix B-3. Images of scheelite (a) reflected light, (b) cathodoluminescence and trace elements LA-ICP-MS

maps in (c) As, (d) Sr, (e) Mo, (f) Nb, (g) Sr, (h) V, (i) La, (j) Y and (k) Eu (thin section HUTT-02, Hutti,

India). ................................................................................................................................................ 155

Appendix B-4. Images of scheelite (a) reflected light, (b) cathodoluminescence and trace elements LA-ICP-MS

maps in (c) As, (d) Sr, (e) Mo, (f) Nb, (g) Sr, (h) V, (i) La, (j) Y and (k) Eu (thin section KOCH-06A,

Kochkar, Russia). ............................................................................................................................. 156

Appendix B-5. Images of scheelite (a) reflected light, (b) cathodoluminescence and trace elements LA-ICP-MS

maps in (c) As, (d) Sr, (e) Mo, (f) Nb, (g) Sr, (h) V, (i) La, (j) Y and (k) Eu (mineral concentrate NORS-

01, Norseman, Australia). ................................................................................................................. 157

Appendix B-6. Images of scheelite (a) reflected light, (b) cathodoluminescence and trace elements LA-ICP-MS

maps in (c) As, (d) Sr, (e) Mo, (f) Nb, (g) Sr, (h) V, (i) La, (j) Y and (k) Eu (thin section MACR-01D,

Macraes, New Zealand). ................................................................................................................... 158

Appendix C-1. Geological settings of the gold deposits selected for tourmaline. ............................................ 159

Appendix C-2. Tourmaline characteristics ...................................................................................................... 161

Appendix C-3. EPMA elements composition in tourmaline from orogenic gold deposits and other localities. 163

Appendix C-4. Analytical conditions for trace element analyses in tourmaline by LA-ICP-MS. ...................... 187

Appendix C-5. LA-ICP-MS trace elements composition in tourmaline from orogenic gold deposits and other

localities. ........................................................................................................................................... 188

Appendix C-6. Correlation matrix among HFSE, LILE and compatible elements for tourmaline from orogenic

gold deposits. Coefficients greater than 0.60 are in bold, coefficients between 0.40 and 0.60 are in

italics. ................................................................................................................................................ 248

Appendix C-7. Comparison between LA-ICP-MS and EPMA analyses for (a) Na, (b) Ca, (c) K, (d) Fe, (e) Al, (f)

Mg, (g) Mn, (h) Ni, (i) Zn, (j) Ti, (k) V and (l) Sc. Red line – 1:1 slope. .............................................. 249

Appendix C-8. Partial Least Square Discriminant Analysis with EPMA major elements for tourmaline in orogenic

gold deposits hosted in various country rock compositions. (a) qw*1-qw*2 loadings, (b) t1-t2 scores, (c)

VIP. Data from the literature: Grzela (2017) and Manéglia (2017). ................................................... 250

Appendix C-9. Binary plot of Mn vs Ti with color variation under non polarized light of EPMA data in tourmaline

from orogenic gold deposits. ............................................................................................................. 251

Appendix C-10. LA-ICP-MS trace element binary plots for tourmaline from orogenic gold deposits (a) ∑REE vs

Sn, (b) ∑REE vs Hf, (c) ∑REE vs Zr, (d) ∑REE vs Nb, (e) ∑REE vs Th, (f) ∑REE vs U and, (g) ∑REE

vs Y. Data from the literature: !!! INVALID CITATION !!! Jiang et al. (2002); Deksissa and Koeberl

xvi

(2004); Roberts et al. (2006); Hazarika et al. (2015); Hazarika et al. (2016); Grzela (2017), Kalliomäki

et al. (2017) and Manéglia (2017). .................................................................................................... 252

Appendix C-11. LA-ICP-MS trace element binary plots for tourmaline from orogenic gold deposits (a) Y vs Zr,

(b) Ta vs Nb, (c) Th vs U, (d) Ga vs Sn, (e) Sc vs V and and, (f) Cr vs Mg. Data from the literature: Jiang

et al. (2002); Deksissa and Koeberl (2004); Roberts et al. (2006); Hazarika et al. (2015); Hazarika et

al. (2016); Grzela (2017), Kalliomäki et al. (2017) and Manéglia (2017). ......................................... 253

Appendix C-12. REE binary plots for tourmaline in orogenic gold deposits (a) (La/Yb)CN vs ∑REE, (b) (La/Sm)CN

vs SmCN, (c) (Gd/Yb)CN vs YbCN, (d) (La/Sm)CN vs ∑LREE and and, (e) (Gd/Yb)CN vs ∑HREE. Data

from the literature: King et al. (1988), Jiang et al. (2002), Deksissa and Koeberl (2004), Roberts et al.

(2006), Hazarika et al. (2015), Hazarika et al. (2016), Grzela (2017), Manéglia (2017) and Kalliomäki

et al. (2017). ...................................................................................................................................... 254

Appendix C-13. Major and minor element variation with zoning in tourmaline from orogenic gold deposits from

LA-ICP-MS maps; (a) microphotograph in plane polarized light of tourmaline from Rosebel (Suriname);

(b) Fe; (c) Mg; (d) Ca; (e) V; (f) Ti; (g) microphotograph in plane polarized light of tourmaline from

Excelsior (USA); (h) Fe; (i) Mg; (j) Ca; (k) V; (l) Ti; (m) microphotograph in plane polarized light of

tourmaline from Hoyle Pond (Canada); (n) Fe; (o) Mg; (p) Ca; (q) V and (r) Ti. Abbreviations: Carb:

carbonate, Chl: chlorite, Qz: quartz, Tur: tourmaline. ....................................................................... 255

Appendix C-14. Partial Least Square Discriminant Analysis of LA-ICP-MS data for tourmaline from orogenic gold

deposits hosted in various country rock compositions and formed at various ages. (a) qw*1-qw*2

loadings, (b) t1-t2 scores and (c) VIP. Data from the literature : Grzela (2017) and Manéglia (2017).256

Appendix C-15. Rare earth elements patterns from LA-ICP-MS data in tourmaline core from orogenic gold

deposits; (a) Hollinger (Canada); (b) Hoyle Pond (Canada); (c) Young Davidson (Canada); (d)

Canadian Malartic (Canada); (e) Roberto (Canada); (f) James Bay (Canada); (g) Excelsior (USA); (h)

Rosebel (Suriname); (i) Essakane (Burkina Faso); (j) New Consort (South Africa); (k) Hira Buddini

(India); (l) Uti (India); (m) Big Bell (Australia) and (n) St. Ives (Australia). ......................................... 257

Appendix C-16. Rare earth elements variations with zoning in tourmaline from orogenic gold deposits from LA-

ICP-MS data; (a) St. Ives (Australia); (b) Royal Hill (Rosebel, Suriname); (c) Young Davidson (Canada);

(d) Hollinger (Canada); (e) Hoyle Pond (Canada) and (f) Hira Buddini (India). ................................. 258

Appendix C-17. Rare earth element patterns in tourmaline from (a) the Lincoln Hill gold deposit (USA), (c)

hydrothermal veins cutting the VMS mineralization at LaRonde (Canada) and (c) Roberto pegmatite

(Canada). .......................................................................................................................................... 259

Appendix C-18. Variation of the REE patterns with the optical zoning in Roberto pegmatite. ........................ 260

Appendix C-19. Trace element binary plots for tourmaline from various deposit types and rocks (a) Y vs Zr, (b)

Ta vs Nb, (c) Th vs U, (d) Ga vs Sn, (e) Sc vs V, (f) Ta vs Zr, (g) Li vs Be, (h) Sr/Sn vs Ba/Ga, and (i)

Ta vs U. Data from the literature: Jiang et al. (2002); Deksissa and Koeberl (2004); Roberts et al. (2006);

Hazarika et al. (2015); Hazarika et al. (2016); Grzela (2017); Kalliomäki et al. (2017) and Manéglia

(2017). .............................................................................................................................................. 261

Appendix C-20. Trace element binary plots for tourmaline from various deposit types and rocks (a) V vs Sr, (b)

Sn vs Zn/Nb, (c) Sn vs Co/Nb, (d) V vs Ni, (e) Sn vs Sr/Ta, (f) Sn vs Co/La, (g) V vs Cr, (h) Sr/Sn vs

Ni/Nb, and (i) Sr/Sn vs V/Be. Data for orogenic gold deposits: Jiang et al. (2002); Deksissa and Koeberl

xvii

(2004); Roberts et al. (2006); Hazarika et al. (2015); Hazarika et al. (2016); Grzela (2017); Kalliomäki

et al. (2017) and Manéglia (2017). .................................................................................................... 262

Appendix D-1. Images of zoned tourmaline (a) under polarized light and LA-ICP-MS maps (b) Ca (c) Ti, (d) Sr,

(e) V, (f) Ga, (g) Ni, (h) Sn, (i) Sc and (j) Cr (thin section EXCE-01, Excelsior, USA). ...................... 263

Appendix D-2. Images of zoned tourmaline (a) under polarized light and LA-ICP-MS maps (b) Fe (c) Cr, (d) Li,

(e) Mn, (f) Ti, (g) Sr, (h) V, (i) Sc and (j) Ni (thin section POND-09B, Hoyle Pond, Canada). ........... 264

Appendix D-3. Images of zoned tourmaline (a) under polarized light and LA-ICP-MS maps (b) Co (c) Cr, (d) Ga,

(e) Ti, (f) V, (g) Sr, (h) Ni, (i) Sn and (j) Sc (thin section RHD-380-29B, Royal Hill, Rosebel, Suriname).

.......................................................................................................................................................... 265

Appendix E-1. Geological settings of the selected gold deposits studied for rutile ......................................... 266

Appendix E-2. Rutile characteristics in the studied orogenic gold deposits .................................................... 272

Appendix E-3. Analytical conditions for trace element analyses in rutile by EPMA ........................................ 276

Appendix E-4. EPMA elements composition in rutile from orogenic gold deposits ......................................... 277

Appendix E-5. Median detection limits for trace element analyses in rutile by LA-ICP-MS ............................ 307

Appendix E-6. LA-ICP-MS trace elements composition in tourmaline from orogenic gold deposits ............... 308

Appendix E-7. Comparison between LA-ICP-MS and EPMA analyses for (a) Ti, (b) Si, (c) Al, (d) Mn, (e) Mg, (f)

As, (g) Fe, (h) V, (i) Cr, (j) Nb, (k) Zr and (l) Sn, (m) Sb, (n) Ta and (o) W........................................ 333

Appendix E-8. Ternary plots for rutile from orogenic gold deposits (a) Ti vs 100x(Fe+Cr+V) vs 1000xSn, (b) Ti

vs 100x(Fe+Cr+V) vs 1000xW and (c) Ti vs 100x(Fe+Cr+V) vs 1000x(Sn+W), (d) Ti vs 100x(Fe+Cr+V)

vs 1000xSb and (e) Ti vs 100x(Fe+Cr+V) vs 1000x(Sb+W), adapted from Clark and Williams-Jones

(2004). Data from this study and literature: Clark and Williams-Jones (2004); Martin (2012); Agangi et

al. (2019). .......................................................................................................................................... 334

Appendix E-9. Binary plots for rutile from orogenic gold deposits of (a) V vs Fe, (b) V vs W, (c) W+Nb+Sb+Ta vs

Fe+V+Cr, (d) Hf vs Zr, (e) Sc vs Zr, (f) Ta vs Zr, (g) Th vs La, (h) Sc vs La, (i) Y vs Yb, (j) Fe vs W, (k)

Ba vs Sn and (l) Ca vs Sr. (a) to (c) are with EPMA data and (d) to (l) are with LA-ICP-MS data. Data

from this study and literature: Clark and Williams-Jones (2004); Scott and Radford (2007); Dostal et al.

(2009); Scott et al. (2011); Martin (2012); Auger (2016); Pochon et al. (2017); Agangi et al. (2019).335

Appendix E-10. Rare earth elements patterns from LA-ICP-MS data in rutile from orogenic gold deposits; (a)

Red Lake; (b) Hollinger; (c) Hoyle Pond; (d) Canadian Malartic; (e) Goldex; (f) Lac Herbin; (g) Beaufor;

(h) Roberto; (i) Sixteen-to-One; (j) Royal Hill, Rosebel; (k) Obuasi; (l) Essakane; (m) Muruntau; (n) Uti,

(o) Big Bell; (p) Tindals and (q) Raleigh. ........................................................................................... 336

Appendix E-11. Partial Least Square-Discriminant Analysis of EPMA data for rutile from orogenic gold deposits

from country rocks metamorphosed to various facies including Si, Fe, Mg, Cr, V, Nb, Ta, W, Sn and

Sb. (a) qw*1-qw*2 loadings and (b) t1-t2 scores, (a) qw*1-qw*3 loadings and (b) t1-t3 scores. Data from

this study and literature: Auger (2016). ............................................................................................. 337

Appendix E-12. Partial Least Square-Discriminant Analysis of LA-ICP-MS data for rutile from orogenic gold

deposits hosted in country rocks with various compositions and metamorphosed to various facies,

xviii

including Nb, Ta, W, Zr, Hf, U, La, Ce, Yb, Y, Sc, Sn, Sb, Cr, Fe, V, Pb, Ba, Na, Al, As and Au. (a) qw*1-

qw*2 loadings and (b) t1-t2 scores, (c) qw*2-qw*3 loadings and (d) t2-t3 scores. ................................. 338

Appendix E-13. Partial Least Square-Discriminant Analysis of EPMA data for rutile in orogenic gold deposits of

various ages. (a) qw*1-qw*2 loadings and (b) t1-t2 scores and scores contributions for each group

including rutile from deposits formed at (c) Archean, (d) Proterozoic, and (e) Phanerozoic. Data from

this study and Auger (2016). ............................................................................................................. 339

Appendix E-14. Trace element binary plots for rutile from various deposit types and rocks (a) V vs Al, (b) V vs

Cr, (c) Ta vs Nb, (d) V vs Fe, (e) V vs Zr and (f) Fe vs U. Plot (a) and (f) refers to the LA-ICP-MS data

and (b), (c), (d), (g) and (h) refers to the EPMA data. ....................................................................... 340

Appendix F-1. (a) Back scattered images of zoned rutile and EPMA maps (b) Cr (c) V, (d) Ta, (e) W, (f) Nb (g)

Sb, (h) Mo, (i) Zr and (j) Al (thin section HOLL-07A, Hollinger, Canada). ......................................... 341

Appendix F-2. (a) Back scattered images of zoned rutile and EPMA maps (b) W (c) Fe, (d) Sb, (e) V, (f) Nb (g)

Zr, (h) Cr, and (i) Al (mineral concentrate BIGB-01, Big Bell, Australia). .......................................... 342

xix

Acknowledgements

Tout d’abord, je tiens à remercier mon directeur de recherche, Georges Beaudoin, qui m’aura guidé à travers

ce projet de recherche. Merci de m’avoir encouragée et de m’avoir aidé à mener à bien de nombreuses

discussions.

Je remercie les membres du jury d’avoir évaluer mon manuscript : Matthieu Harlaux, Bertrand Rottier, ainsi que

Crystal Laflamme.

Je voudrais ensuite remercier toutes les personnes qui ont contribuées de loin ou de prêt à compléter ma

collection d’échantillons. Certaines auront manifestées un grand intérêt et donnés leur set complet de lames

minces alors que d’autres m’auront clairement mentionnées une cause perdue… La liste est longue et les

personnes se reconnaitront.

Je voudrais ensuite remercier toutes les personnes qui m’ont assisté lors des techniques analytiques telles que

Marc Choquette, André Ferland, Dany Savard, Marko Kudrna Prasek et Philippe Pagé. Je tiens à remercier tout

particulièrement Sheida Makvandi, pour avoir été ma collègue et amie, mais aussi pour avoir bâti le socle de

l’édifice de la chaire de recherche dans laquelle nous avions travaillé ensemble, c’est-à-dire les analyses

multivariées, le travail en amont des analyses et les scripts qui vont avec ! Un grand merci à Émilie Bédard pour

son amitié et son efficacité au travail ! Merci à Anne-Aurélie Sappin pour ses petits coups de pouce de senior et

son entrain infini. Je remercie ensuite toutes les personnes du département de Géologie et Génie Géologique

de l’Université Laval : François Huot, Guylaine et sa bonne humeur, Edmond, Julia, Marcel, Josée…

J’ai une pensée toute particulière pour mes amis et collègues de travail, de prêt et de loin : Donald, mon fidèle

ami de bureau avec son accent franc-ontarien que j’ai fait répéter de nombreuses fois et qui a été mon double

en canot de rivière, Clovis, Tom, FX, Victor, Renato et son éternel sourire, Nathan qui manque de sourire,

Débora, Nicolas, sans oublier Stéphanie : on aura mis du temps à s’adresser la parole mais c’est pour une

amitié infinie.

Je remercie également mes parents qui m’ont permis d’arriver où j’en suis aujourd’hui et tout particulièrement

ma sœur qui m’aura inculqué cette foi de battante et cette capacité de croire en moi-même.

Finalement, ma plus grande gratitude va à Roman. Si une thèse n’est définitivement pas le travail d’une seule

personne, Roman serait deuxième auteur. Je te remercie pour ton soutien quotidien, tes idées, tes

connaissances, ton investissement, ton temps, ta foi envers mon projet... La liste est tellement longue que les

mots me manquent. Merci de m’avoir donné les ressources morales et matérielles pour mener à bien ce projet

et clore ce chapitre de nos vies.

xx

Foreword

All chapters in this thesis were written by the author. The first and second chapters entitled “Trace element

composition of scheelite in orogenic gold deposits” and “Chemical composition of tourmaline in orogenic gold

deposits” has been published and submitted, respectively, to Mineralium Deposita. The third chapter entitled

“Texture and trace elements composition of rutile in orogenic gold deposits” is in preparation for submission to

a scientific journal. The first author of the articles, Marjorie Sciuba, completed the sample collection, prepared

the samples, carried out the analytical work and interpreted the data. Co-authors to the articles include Georges

Beaudoin (Université Laval), research director of the Ph.D. project, Sheida Makvandi, (Université Laval), post-

doctoral fellow (Université Laval), and Donald Grzela, M.Sc. student at Université Laval.

1

Introduction

Indicator mineral method

The indicator mineral technique has been developed significantly since the 1980s and it has been successfully

used in geochemical exploration, especially for exploration in glaciated terrains. A broad set of indicator

minerals are now available for many deposit types such as diamond-bearing kimberlite (e.g. McClenaghan

and Kjarsgaard 2007), metamorphosed volcanogenic massive sulfides (VMS; e.g. Heimann et al. 2005),

porphyry Cu deposits (e.g. Averill 2011; Kelley et al. 2011), magmatic Cu-Ni-PGE deposits (e.g. Averill 2001,

2011; McClenaghan 2011), Mississipi Valley Type (MVT) Pb-Zn (e.g. Paulen et al. 2011; Oviatt et al. 2013)

and some other deposit types. Indicator minerals are commonly recovered from quaternary formations such

as soil, glacial, stream or aeolian sediments. Indicator mineral dispersion in the surficial environment may

potentiall lead to discovery of mineral deposits. This technique was successfully used to discover several

deposits, for example Casa Berardi (Québec, Canada; Sauerbrei et al. 1987). McClenaghan (2005) defines

indicator minerals “as mineral species that, when appearing as transported grains in clastic sediments,

indicate the presence in bedrock of a specific type of mineralization, hydrothermal alteration or lithology”. An

indicator mineral may be the mineral of interest itself, such as gold or mineral associated with the

mineralization. Indicator minerals are recovered from surface samples such as till, stream sediment or soil.

After mineral separation, they are counted and investigated for different features such as shape, texture or

roundness that inform on the transport distance and the potential source. Indicator minerals are particularly

useful for reconnaissance exploration in glaciated terrains where physical disaggregation is important

(McClenaghan 2005). The indicator mineral method has many benefits for geochemical exploration including

(1) large targeted areas are favorable for blind discoveries, (2) several deposit-types can be targeted in a

single survey, (3) mineral dispersion can provide evidence of the distance from the source (Averill 2001), (4)

indicator mineral dispersal trains are potentially larger than dispersion patterns using stream sediment

samples such that this increases the potential for discovery (Kelley et al. 2011). The indicator mineral method

is used not only for mineral deposit exploration but also for rock types and geological terranes (Friedrich 1992;

Stendal and Theobald 1994). The indicator mineral method has mostly been developped by case studies

around known mineral deposits and syntheses have reviewed the state-of-the-art knowledge on the method

(Thorleifson and McClenaghan 2003; McClenaghan 2005; Paulen and McMartin 2010). Mineral deposit types

explored using indicator mineral method include gold, diamond, VMS, MVT, porphyry Cu, magmatic Ni-Cu-

PGE, W-Mo, Cu skarn and greisen deposits. Indicator minerals have physical and chemical properties that

make them chemically stable and resistant to mechanical abrasion. Most of them are easy to identify and

have specific properties (i.e. density, magnetic susceptibility, colour under UV light, etc.) for the mineral

separation.

Physical properties

Indicator minerals have high specific gravity (S.G > 3.2; Averill 2001) favoring their concentration in

hydrodynamic traps during transport. Differences in density between indicator mineral species are used for

mineral separation. According to their relative hardness, indicator minerals may be reshaped during transport.

Soft minerals such as gold (hardness: 2.5) are more malleable and deformable than harder minerals such as

tourmaline (7.0-7.5) and rutile (6-6.5). Others such as galena are sectile. As a consequence, soft minerals are

reshaped during transport (Averill 2001). The initial size of indicator minerals is controlled by processes during

2

crystallization. They may be fractured by hydration during volcanism or pre-glacial weathering and abraded

during transport (McClenaghan 1994; McClenaghan and Kjarsgaard 2001). Cleavage planes in minerals

facilitate fracturing and mineral comminution. Fracturing is part of the factor controlling grain size and the

relative abundance of indicator minerals in glacial drift (McClenaghan 1994; McClenaghan and Kjarsgaard

2001). Fracture-resistant minerals such as Mg-ilmenite are generally coarse-grained (0.5-1.0 mm) compared

to fracture-prone minerals such as Cr-pyrope that easily breaks into smaller grains (0.25-0.5 mm; Averill

2001). High magnetic susceptibility (e.g. magnetite) and fluorescence properties under UV light (e.g.

scheelite) are additional physical properties facilitating mineral separation and selection (Averill 2001).

Colourful indicator minerals are visually more distinctive and, thus, easier to recognize and select.

Chemical properties

Useful indicator minerals should be chemically stable in the surficial environment and resistant to weathering.

Sulfides may be used as indicator minerals in some conditions. Most sulfides with the possible exception of

chalcopyrite and sphalerite, are unstable under oxidizing conditions whereas arsenides such as loellingite

(FeAs2) are relatively stable (Averill 2001). Processes such as pre-glacial supergene alteration of the mineral

orebody or in-situ weathering and oxidation of transported grains may affect indicator minerals and especially

sulfides. Such processes may partially to completely destroy sulfides and lower the indicator minerals

abundance in till (Averill 2001).

During the last decades, research on indicator minerals focused on characterizing indicator mineral

composition to constrain mineral provenance (e.g. Stendal and Theobald 1994; McClenaghan and Kjarsgaard

2007; Makvandi et al. 2012; McClenaghan et al. 2012a; McClenaghan et al. 2012b; Nadoll et al. 2012; Boutroy

et al. 2014; Nadoll et al. 2014; Makvandi et al. 2015; McClenaghan et al. 2015; Auger 2016; Makvandi et al.

2016a; Makvandi et al. 2016b; Manéglia et al. 2018; Grzela et al. 2019). Advances on analytical techniques,

and especially LA-ICP-MS, enable to quantify more precisely the mineral trace element composition, on

smaller and smaller volumes.

For instance, the composition of Fe-oxides including magnetite and hematite are documented for

Volcanogenic Massive Sulfide (VMS), Iron Oxyde Copper Gold (IOCG), Iron Oxyde Apatite (IOA), Banded

Iron Formation (BIF), porphyry, skarn, Fe-Ti, V, Cr, Ni-Cu, clastic Pb-Zn and other deposit types (e.g. Dupuis

and Beaudoin 2011; Dare et al. 2012; Makvandi et al. 2012; Nadoll et al. 2012; Boutroy et al. 2014; Dare et

al. 2014; Nadoll et al. 2014; Makvandi et al. 2015; Makvandi et al. 2016a; Makvandi et al. 2016b). Apatite is

another example of commonly used indicator mineral that has a well characterized mineral composition (e.g.

Bouzari et al. 2016; Hazarika et al. 2016; Mao et al. 2016; Adlakha et al. 2017; Wilkinson et al. 2017). The

trace element composition of minerals such as magnetite, hematite and apatite can now be used with

confidence to determine their provenance in indicator mineral surveys and to trace various deposit types.

Developing indicator mineral methodology for orogenic gold

exploration

Orogenic gold deposits represent one of the major gold source worldwide (Phillips and Powell 2014) for the

mineral industry and represent about 45 % of gold deposits containing more than 1 Moz Au (production +

reserves), compared to other gold deposit types including intrusion-related deposits (28% for porphyry, skarn,

manto, Carlin and breccia-pipe), epitermal (25 %) and paleoplacers (3 %; Goldfarb et al. 2005). Orogenic gold

3

deposits are defined by Groves et al. (1998) as gold deposits that formed at temperatures of 180-700°C and

pressures of

4

Characterize the mineral composition by statistical analysis including elemental binary and ternary

plots as well as multivariate statistics including PCA and PLS-DA, according to the selected

geological settings of orogenic gold deposits.

Compare the composition of scheelite, tourmaline and rutile from orogenic gold deposits with those

from other deposit types and environments available in literature.

Figure 0-1. Distribution of the selected orogenic gold deposits in this study, (a) in the world Map is adapted from the Canada Geological Survey database; (b) in the Abitibi subprovince, Canada; map modified from Poulsen et al. (2000) and (c) in the Yilgarn craton, Australia. Map is adapted from Robert et al. (2005).

5

Table 0-1. List of the selected deposits for the study

Location Scheelite Tourmaline Rutile

North American Shield

Meliadine district x x

Giant x

Red Lake x

Roberto x x

James Bay x x

Dome x x x

Hollinger x x x

Hoyle Pond x x

Young Davidson x x x

Canadian Malartic x x x

Beaufor x x

Goldex x

Lac Herbin x

Sigma-Lamaque x x

North American cordillera

Alaska-Juneau x

Excelsior x

Alleghany x

Amazon craton

Rosebel x x x

Sao Francisco craton

Cuiaba x

Massif Central

Salsigne x

West African craton

Essakane x x x

Damara orogen

Navachab

x

Location Scheelite Tourmaline Rutile

Tanzanian craton

Buzwagi x

Bulyanhulu x

North Mara x

Navachab x

Kaapvaal craton

New Consort x x

Dharwar craton

Hutti x x

Uti x

Hira Buddini x

Uralide

Kochkar x

Tien Shan

Kumtor x x

Muruntau x

Yilgarn craton

Marvel Loch x

Nevoria

Edward’s Find x

Tarmoola x

Transvaal x

Paddington x

Mt Pleasant x

Big Bell x x

Waroonga x

Harbour Lights x

Kanowna Belle x

Tindals x

Raleigh x

St. Ives x x

Wallaby x

Porphyry x

2

Sunrise Dam x

Norseman x

Mt Charlotte

x

Tasman orogen

Fosterville x

Otago schist

Macraes

3

Thesis outline

The PhD thesis presents the outcome of the study as a succession of three chapters as following:

The general introduction about indicator mineral method, the problematic, the research objectives and the

followed methodology and the thesis outlines are presented at the beginning of the manuscript.

Chapter 1 examines the case of scheelite, as indicator mineral for orogenic gold deposits. This chapter is part

of a publication released in Mineralium Deposita: Sciuba, M., Beaudoin, G., Grzela, D., and Makvandi, S.

(2019) Trace element composition of scheelite in orogenic gold deposits, Mineralium Deposita. Co-authors

include Georges Beaudoin, the thesis supervisor, Donald Grzela, M.Sc. student and Sheida Makvandi, post-

doctoral fellow. DOI: 10.1007/s00126-019-00913-4

Chapter 2 examines the case of tourmaline, as indicator mineral for orogenic gold deposits. This chapter is

part of a publication under review at Mineralium Deposita: Sciuba, M., Beaudoin, G., and Makvandi, S.

(submitted) Chemical composition of tourmaline in orogenic gold deposits. Co-authors include Georges

Beaudoin, the thesis supervisor and Sheida Makvandi, post-doctoral fellow.

Chapter 3 examines the case of rutile, as indicator mineral for orogenic gold deposits. This chapter will be

submitted to a scientific journal as follow: Sciuba, M. Beaudoin, G. Texture and trace element composition of

rutile in orogenic gold deposits (in prep). Co-author is Georges Beaudoin, the thesis supervisor.

The general conclusion and recommendations for future work are presented at the end of the manuscript.

Appendices A to F contain supplementary materials that support the articles. Appendices A and B are

associated with chapter 1 (scheelite), appendices C and D with chapter 2 (tourmaline), and appendices E and

F with chapter 3 (rutile).

4

Chapter 1. Trace element composition of

scheelite in orogenic gold deposits

1.1. Résumé

La scheelite de vingt-cinq gisements d’or orogénique représentatifs avec des contextes géologiques variés a

été analysée par microsonde électronique (EPMA) et laser ablation et spectroscopie de masse avec plasma

couplée par induction (LA-ICP-MS) pour établir des paramètres géochimiques discriminants pour contraindre

les études de minéraux indicateurs pour l’exploration aurifère. La scheelite des gisements d’or orogénique a

cinq patrons d’éléments des terres rares (ETR) incluant un patron en forme de cloche avec une anomalie (i)

positive ou (ii) négative en Eu; (iii) un patron plat avec une anomalie positive en Eu et, moins communément,

(iv) un patron enrichi en ETR légères, et v) un patron enrichi en ETR lourdes. Les patrons des ETR sont

interprétés comme le reflet de la source des fluides hydrothermaux ou le partage des ETR avec les minéraux

co-précipités. La scheelite des gisements formés dans des roches métamorphisées depuis le faciès des

schistes verts supérieurs au faciès des amphibolites inférieures ont une teneur faible en ETR, Y, et Sr et une

teneur élevée en Mn, Nb, Ta et V, comparé à la scheelite formée dans des roches métamorphisées sous le

faciès des schistes verts moyen. La scheelite des gisements encaissés dans des roches sédimentaires a une

teneur élevée en Sr, Pb, U et Th, et une teneur faible en Na, ETR et Y comparé à la scheelite des gisements

encaissés dans des roches felsiques à intermédiaires. Les analyses statistiques incluant des diagrammes

élémentaires et des statistiques multivariées avec la méthode d’analyse discriminante des moindres carrées

(PLS-DA) montrent que le faciès métamorphique des roches encaissantes, et la composition de l’encaissant

régional exercent un fort contrôle sur la composition de la scheelite. Ceci résulte des échanges fluide-roche

lors de la circulation des fluides jusqu’au site de minéralisation de l’or. Les PLS-DA et les diagrammes binaires

de ratios élémentaires montrent que la scheelite des gisements d’or orogénique possède une signature

distincte en Sr, Mo, Eu et Sr/Mo, mais une signature en ETR indistinguable, comparée à celle de la scheelite

des autres types de gîtes.

1.2. Abstract

Scheelite from twenty-five representative orogenic gold deposits from various geological settings was

investigated by EPMA (Electron Probe Micro-Analyzer) and LA-ICP-MS (Laser Ablation-Inductively Coupled

Plasma-Mass Spectrometer) to establish discriminant geochemical features to constrain indicator mineral

surveys for gold exploration. Scheelite from orogenic gold deposits displays five REE patterns including a bell-

shaped pattern with a (i) positive or (ii) negative Eu anomaly; iii) a flat pattern with a positive Eu anomaly and,

less commonly, (iv) a LREE enriched pattern, and (v) a HREE enriched pattern. The REE patterns are

interpreted to reflect the source of the auriferous hydrothermal fluids and, perhaps, co-precipitating mineral

phases. Scheelite from deposits formed in rocks metamorphosed at upper greenschist to lower amphibolite

facies have low contents in REE, Y, and Sr, and high contents in Mn, Nb, Ta and V, compared to scheelite

formed in rocks metamorphosed below the middle greenschist facies. Scheelite from deposits hosted in

sedimentary rocks has high Sr, Pb, U and Th, and low Na, REE and Y, compared to that hosted in felsic to

intermediate rocks. Statistical analysis including elemental plots and multivariate statistics with PLS-DA

(Partial Least Square-Discriminant Analysis) reveal that the metamorphic facies of the host rocks, as well, as

the regional host rock composition exert a strong control on scheelite composition. This is a result of fluid-

rock exchange during fluid flow to gold deposition site. PLS-DA and elemental ratio plots show that scheelite

5

from orogenic gold deposits have distinct Sr, Mo, Eu, As and Sr/Mo, but indistinguishable REE signatures,

compared to scheelite from other deposit types.

1.3. Introduction

The association between gold and scheelite in orogenic gold deposits has long been recognized. Goldfarb et

al. (2005) review the characteristics of orogenic gold deposits. In many deposits, scheelite predates and/or is

contemporaneous with gold deposition, such as in the Val-d’Or district, Canada (Beaudoin and Pitre 2005),

at Mt. Charlotte, Australia (Mueller 1991) or Charmitan, Uzbekistan (Graupner et al. 2010). Scheelite is a

major mineral in greisen and skarn (Xiong et al. 2006; Ren et al. 2010; Song et al. 2014; Guo et al. 2016;

Poulin 2016; Poulin et al. 2016; Poulin et al. 2018), and a minor mineral in Cu-(Mo-Au) porphyry deposits

(Poulin 2016; Poulin et al. 2016; Sun and Chen 2017; Poulin et al. 2018), where it occurs in veins or

disseminated in altered rocks. Scheelite is also an accessory mineral in aplite, pegmatite and metamorphosed

sedimentary exhalative Fe-Mn (Brugger et al. 1998; Uspensky et al. 1998) and volcanogenic massive

sulphides deposits (Poulin 2016; Poulin et al. 2016; Poulin et al. 2018).

The indicator mineral technique is used in exploration using overburden sediments for several deposit types.

Discriminant geochemical features in major, minor and trace elements of indicator minerals may be used to

recognize a deposit type. For instance, Cr-rich spinel and Cr-rich garnet are indicators for diamond-bearing

kimberlite (Gurney 1984; Fipke et al. 1995; McClenaghan and Kjarsgaard 2007), and Ni-Cu mineralization

(Aumo and Salonen 1986; Peltonen et al. 1992; Somarin 2004), whereas magnetite has been shown to be

useful to fingerprint various mineral deposit types (Dupuis and Beaudoin 2011; Boutroy et al. 2014; Dare et

al. 2014). Scheelite is considered an indicator mineral for orogenic gold (McClenaghan and Cabri 2011) and

tungsten deposits (Lindmark 1977; Toverud 1984; Johansson et al. 1986). In indicator mineral surveys,

scheelite is recovered from the heavy mineral fraction or overburden sediments, but the deposit type at the

source of the scheelite grains cannot, currently, be determined.

Scheelite (CaWO4) and powellite (CaMoO4) form a partial solid solution where Mo6+ substitutes for W6+ (Tyson

et al. 1988). Pure scheelite is bluish under short wave fluorescent light, whereas Mo-rich scheelite is typically

yellow in color (Van Horn 1930; Shoji and Sasaki 1978). Scheelite is luminescent under an electron beam

allowing to study textural zonation and successive scheelite generations in relationship with their trace

element composition. The REE, Y, As, and Sr content in scheelite have a minor effect on the

cathodoluminescence (CL) response (Brugger et al. 2000a; MacRae et al. 2009; Poulin 2016; Poulin et al.

2016), whereas Mo variation is associated with CL zoning, (Poulin 2016; Poulin et al. 2016). The CL zoning

may result from primary crystallization or from multi-stage evolution (Brugger et al. 2000a).

Replacement of W by Mo and Ca by Sr, Pb, Fe, Mn, Ba and REE have been reported (Cottrant 1981;

Raimbault et al. 1993; Ghaderi et al. 1999) and traces of Na, V, Nb, Ta, S, As, Pb, U, Th, Mn, Fe, Au, Ba, B,

Co, Cr, K, Ni, Sb Sc, Zn, Bi, Cu, Sn, Zn, Li, Ti and Rb have been measured in variable amounts in scheelite

from various types of deposits (Anglin 1992; Eichhorn et al. 1997; Zhigang et al. 1998; Ghaderi et al. 1999;

Brugger et al. 2000a; Brugger et al. 2000b; Brugger et al. 2002; Xiong et al. 2006; Liu Yan et al. 2007; Dostal

et al. 2009; Graupner et al. 2010; Peng et al. 2010; Ren et al. 2010; Song et al. 2014; Hazarika et al. 2016;

Poulin 2016; Poulin et al. 2016; Fu et al. 2017; Sun and Chen 2017).The high REE concentrations (~10-5,000

ppm; Uspensky et al. 1998) in scheelite have been used for Sm-Nd geochronology in order to date the gold

mineralization (Anglin 1992; Anglin et al. 1996; Frei et al. 1998; Uspensky et al. 1998; Kempe et al. 2001;

Roberts et al. 2006) whereas the Sr and Nd isotopic compositions have been used to constrain the sources

and the pathway of auriferous hydrothermal fluids (Bell et al. 1989; Mueller et al. 1991a; Kent et al. 1995;

6

Darbyshire et al. 1996; Frei et al. 1998). Most of the studies on Sr and Nd isotopic composition of scheelite

from orogenic gold deposits conclude that the fluids are derived from the mantle and/or the lower crust (Bell

et al. 1989; Mueller et al. 1991a; Darbyshire et al. 1996; Voicu et al. 2000), with the exception of the Muruntau

gold deposit where Kempe et al. (2001) concluded that fluids were most probably derived from the local host

rocks. Calcium is likely derived from the regional host rocks, whereas, W is considered to be derived from the

hydrothermal fluids (Goldfarb and Groves 2015). Isotopic studies of scheelite have shown that Sr is partly

derived from the local host rocks (Mueller et al. 1991a; Darbyshire et al. 1996; Ghaderi et al. 1999; Brugger

et al. 2002), whereas Pb and Nd have more complex sources at the local and regional scales (Brugger et al.

2002). Poulin (2016) discriminated the trace element signatures of metamorphic scheelite to that from

magmatic and hydrothermal settings using the Eu anomaly vs Mo/Sr. Previous studies, however, do not

provide a common, comprehensive, set of minor and trace elements contents in orogenic gold deposit

scheelite.

Defining the texture, luminescence properties, and trace element composition of scheelite from orogenic gold

deposits could be used to identify and track these deposits in overburden sediments. In this study, we present

textural and chemical characteristics of scheelite from 25 orogenic gold deposits, including 13 world-class

examples, that represent a large variation in host rock composition and age, metamorphic facies and

mineralization age, in order to characterize scheelite from this deposit type. Mineral texture was investigated

by CL and composition was determined by Electron Probe Micro Analyzer (EPMA) for major and minor

elements, and by Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) for minor and

trace elements. Discriminant binary and ternary diagrams, box plots and multivariate statistics including

Principal Component Analysis (PCA) and Partial Least Square-Discriminant Analysis (PLS-DA) are used to

characterize scheelite composition from various geological settings within the orogenic gold deposit type.

Furthermore, we compare the chemical composition of scheelite from orogenic gold deposits to that from

other deposit types in order to define discriminant criteria that would be useful to identify the source of

scheelite in indicator mineral surveys.

1.4. Geological settings of the selected orogenic gold

deposits

Typical samples of gold mineralization were selected from 13 world-class (Goldfarb et al. 2005) and 12

additional orogenic gold deposits and districts (APPENDIX 1a). The set of samples is considered to represent

largely the variability of orogenic gold deposit characteristics. The origin of the Kumtor, Canadian Malartic and

Young Davidson deposits is still debated, but we follow Goldfarb et al. (2005) and consider they belong to the

orogenic type. Mueller (1997) and Mueller et al. (2004) considered the Nevoria gold deposit as a skarn,

whereas