explomin.ggl.ulaval.ca...ii résumé la scheelite, la tourmaline et le rutile des gisements d’or...
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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
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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
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des gisements d’or orogénique et celui provenant d’environnement hydrothermaux et métamorphique-
hydrothermaux.
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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.
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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
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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
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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
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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
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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
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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)
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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
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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
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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
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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
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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
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(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
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(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,
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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
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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.
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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.
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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
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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
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deposits are defined by Groves et al. (1998) as gold deposits that formed at temperatures of 180-700°C and
pressures of
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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).
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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
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Sunrise Dam x
Norseman x
Mt Charlotte
x
Tasman orogen
Fosterville x
Otago schist
Macraes
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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).
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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
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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;
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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