Regional-scale studies

Bonnefond corridor
Alexandra Daniela Cazares – PhD 
The Bonnefond corridor is a sector of the Val-d’Or orogenic gold vein field, in the Neoarchean Abitibi sub-province (Québec), south and southwest of the Bourlamaque batholith. The volcanic country rocks are intruded by several intrusive bodies, both syn- and post-volcanic, including the Bonnefond South tonalitic to dioritic complex and the New Louvre tonalite sill. The intrusions and their immediate host rocks are cut by second- and third-order shallow-dipping (15 and 45º) shear zones that host gold-bearing quartz-carbonate-tourmaline veins. Efficient exploration requires a better understanding of the relations between the intrusion age, petrology, and geochemistry, and that of the volcanic host rocks and the overlapping VMS (e.g., Louvicourt) and orogenic gold mineralized systems.
Objectives: i) characterize the petrological and geochemical evolution of the volcanic and intrusive rocks; ii) constrain the chronology of intrusive activity; iii) establish the paragenetic sequence of mineralization and alteration; iv) define the structural framework of the shear zones and veins; v) compare with other gold deposits hosted in tonalitic and dioritic intrusions.

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Hope Bay

Ruth Orlóci-Goodison – PhD 

Hope Bay is a strongly deformed, 100 km long greenstone belt in the Neoarchean Slave Province (Nunavut) that contains several gold deposits formed during the main D2 deformation event (Sherlock et al., 2012). It is metamorphosed to lower greenschist facies, with higher metamorphic grade (lower amphibolite) at the contact with surrounding granite/gneiss. Several smaller zones of higher metamorphic grade are recognized proximal to gold mineralization, suggesting a localized higher thermal regime or carbonic fluid flux as in Timmins/Kirkland Lake (Thompson, 2005). This relationship needs to be documented in detail to assess its control on the localization of gold mineralization and to develop innovative exploration guides.

Objectives: i) map the structural patterns and distribution of metamorphic facies with emphasis on metamorphic “hot spots”; ii) estimate rock/fluid thermobarometric conditions; iii) establish the geodynamic setting of volcanism and metamorphism/deformation; iv) constrain the chronology of deformation and metamorphism.

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Hope Bay-Doris Structure

Louis-Dominique Lavallée – MSc 

The Doris gold deposit, located in the Hope Bay greenstone belt of Nunavut, consists of folded quartz-tourmaline-carbonate veins hosted within magnesium-rich tholeiitic basalts in the footwall and iron-titanium-rich basalts in the hanging wall. These veins are crosscut by a Proterozoic gabbroic dyke. This project aims to conduct a detailed structural characterization of the deposit and its proximal alteration footprint.

Objectives: i) Define the structural context of mineralization, establish the relative chronology of deformation phases, and identify structural controls on vein emplacement, geometry, and gold grade distribution. ii) Characterize the petrology (petrography and geochemistry) of the host rocks. iii) Establish the paragenetic sequence of gold mineralization. iv) Determine the mineralogy and chemical variations of proximal hydrothermal alteration facies associated with the gold-bearing veins.

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     Deposit scale studies

 

Four deposit-scale studies aim to date fluid flow events and understand the source and flow of hydrothermal fluids forming gold deposits. Each PhD-level case study will have similar objectives, activities, anticipated results, milestones, and deliverables, whereas a MSc-level case study has a more restricted scope (see below). Each of the case studies investigates different geological settings, which will provide a broad understanding of the variations in age and fluid sources forming orogenic gold deposits. In particular, two of the proposed studies (Meliadine and Amaruq/Meadowbank) will investigate polyphased gold deposits in Archean rocks deformed during multiple distinct Archean and Paleoproterozoic orogenic events, building on previous and current studies of their geological, structural and chronological settings, but for which the fluid sources and timing of gold mineralization remain to be further unraveled.

Objectives: i) date auriferous hydrothermal fluid flow events using phosphate U/Pb geochronology on grains related to gold deposition; ii) establish the source of fluids, gold ligands, and metals; iii) present a framework relating the auriferous fluid events to the tectonometamorphic evolution of the country rocks.

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Hope Bay source and ages of fluids
Diego Oswaldo Ruiz Portilla – PhD
This study will build upon the regional-scale study of the greenstone belt. The age of gold mineralization in the Hope Bay belt is constrained only by dominant D2 deformation (Sherlock et al., 2012). An intriguing feature of the Hope Bay greenstone belt is the lack of terrane-bounding crustal shear zones (Sherlock et al., 2012), commonly interpreted to control the flow of hydrothermal fluids. The age of mineralization in relation to metamorphism and deformation remains speculative, whereas no information exists on the origin and evolution of the hydrothermal fluids for this region, where the greenstone belt rests on an old, metamorphosed crystalline basement.

Meliadine source and age of fluids
Ahmed Hamdy – PhD
Meliadine hosts a series of Banded-Iron Formation (BIF) associated orogenic gold deposits located along the Pyke Fault, in Nunavut. Dating of arsenopyrite by Re/Os yields a range of model ages from 2.3 to 1.8 Ga (Lawley et al., 2015). Late xenotime in quartz veins and altered host rocks yielded SHRIMP ages of 1858±10 Ma (Lawley et al., 2015) similar to monazite 1854±6 Ma (Carpenter et al., 2005). However, the relationship of the dated phosphate grains with gold mineralization is equivocal. Thus, the age of gold mineralization is uncertain, and the source of fluids has not been investigated, such that the origin of the gold mineralization hosted in Archean rocks, overprinted by Paleoproterozoic events, remains mysterious, thus hampering efficient exploration in similar terranes.

Amaruq/MeadowBank source and age of fluids
Maria Reyes – PhD 
Amaruq and Meadowbank gold deposits are both associated with Archean iron formations and ultramafic volcanic rocks in Nunavut. The gold mineralization consists of both stratabound disseminated replacement and later veins, indicating several hydrothermal events (Valette et al., 2020; Janvier et al., 2015). In addition, at Amaruq, gold-bearing arsenopyrite is metamorphosed to löllingite and recrystallized to arsenopyrite with free gold during retrograde Trans-Hudson Paleoproterozoic metamorphism (Lauzon et al., 2020). Arsenopyrite Re/Os geochronology yields Late Archean model ages, suggesting older hydrothermal events overprinted by Paleoproterozoic deformation.

Bonnefonds source and age of fluids
François-Xavier Bonin – MSc 
This study will complement the regional-scale study of the Bonnefond corridor and current research on the age of gold mineralization and source of hydrothermal fluids in the Val-d’Or vein field. It will build on previous and ongoing work by the team in the Val-d’Or vein field, where we have conducted detailed studies on several gold deposits (Beaudoin & Chiaradia, 2016; Herzog et al. submitted), but which are lacking in the Bonnefond corridor.
Objectives: i) date hydrothermal fluid flow events using paragenetically constrained phosphate U/Pb geochronology; ii) establish the source of fluids, gold ligands, and metals.  

Geomechanical modeling of deformation/fluid flow study
Hadi Hasanzadehshooiili – PDF 
A common feature in orogenic gold deposits is characterized by strain partitioning within and/or between more competent intrusive rocks and less competent volcanic country rocks, which results in an abundance of shear and dilatational strain structures, like in Triangle and several other deposits in the Val-d’Or vein field. These variations in shear and dilatational strain localization between the intrusive bodies and their host rocks are a major control on the distribution of gold mineralization. A better understanding of the relationships between deforming intrusions, weaker host rocks, and fluid flow is crucial.
Objectives: i) measure rock properties for various lithologies and their alteration products; ii) model rock deformation and fluid flow; iii) establish parameters favorable for localized strain and dilation; iv) compare modeling results to Triangle and other intrusion-hosted gold deposits in the Val-d’Or vein field.

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     Indicator Minerals

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Tourmaline
Eduardo Valentin dos Santos – PhD 
Tourmaline occurs in a wide range of geological environments, such as VMS and SEDEX deposits with associated tourmalinites, various skarn, porphyry Cu-Mo, greisen W-Sn-Mo hydrothermal veins, unconformity-associated uranium, IOCG, emerald occurrences, aplite and pegmatite, metasedimentary rocks, including meta-evaporites. Samples from a range of deposits are available for study from the collections of Professor Beaudoin, in part from the initial mandate of the Chair, while collaborators and colleagues from academia, government, and industry, with experience in key deposits and geological occurrences, will provide additional samples.
Objectives: i) Document tourmaline major and trace element composition in various geological settings. The study will complement the investigation of tourmaline chemical composition undertaken during the initial mandate of the Chair. ii) Define chemical criteria to fingerprint tourmaline sourced from orogenic gold deposits. 

Long-distance detection of gold deposits: Meadowbank and Amaruq (Nunavut)
Wasiq Lutfi – PhD
The PhD project is a component of a research program on the Amaruq and Meadowbank gold deposits in Nunavut, during which several studies have been conducted to describe in detail the Quaternary geology and dispersion of the gold deposit’s chemical and indicator mineral signature by ice flow. The project objective is to determine the ultimate distance at which we can track the trace of an orogenic gold deposit, using its chemical signature and the chemical composition of indicator minerals (chalcopyrite, scheelite, tourmaline, native gold). The project will investigate the dispersal of orogenic gold in the region of the Meadowbank and Amaruq deposits. It will document the chemical signature of indicator minerals at Meadowbank and other mineralized occurrences in the region to complement that of Amaruq. It will determine the ultimate distance at which the specific signature of a gold deposit can be detected, in relation to its glacial history, to define exploration methodologies for exploration for orogenic gold deposits under glacial cover.

Arsenopyrite IM
Martin Roglic – PhD 
Arsenopyrite is a common gold-associated mineral for which trace element data are scarce. This hampers the application of indicator minerals for deposits where arsenopyrite is abundant, such as orogenic gold deposits in Nunavut.
Objectives: i) measure the major and trace element composition of arsenopyrite from a range of geological settings; ii) define chemical criteria to fingerprint arsenopyrite sourced from orogenic gold deposits; iii) carry out case studies to test the application of arsenopyrite for provenance surveys. 

Chalcopyrite IM – Chemical composition of chalcopyrite: Application to exploration
Albert Vanelinke – PhD 
Ongoing study on chalcopyrite major and trace element composition (E. Caraballo, PhD candidate) has focused on orogenic, Ni-Cu, and VMS deposits, in addition to more limited data on other chalcopyrite sources, including porphyry copper deposits. The limited dataset on porphyry copper deposits limits the use of chalcopyrite in provenance studies.
Objectives: i) measure the major and trace element composition of chalcopyrite in representative porphyry Cu-Mo-Au deposits; ii) define chemical criteria to fingerprint chalcopyrite sourced from orogenic gold and porphyry deposits; iii) develop a methodology to use chalcopyrite for orogenic gold deposits exploration. 

Vectoring and fertility

Three similar case studies on orogenic gold deposits with different characteristics and in contrasting geological settings to devise innovative indicator mineral vectoring and fertility assessment tools to target gold oreshoots in a deposit. These will complement ongoing studies at Triangle (Val-d’Or, G. Pedemonte, PhD candidate), Augmitto-Bouzan (Rouyn-Noranda, R. dos Santos, PhD candidate), and Meliadine (Nunavut, P. Mongeau, MSc candidate). Each will have similar objectives, apply similar but adapted methods to each case study, and yield similar results and milestones presented for the three projects below.
Objectives: i) measure the chemical and isotope composition of minerals associated with gold deposition; ii) identify textural, chemical, and isotopic features associated with gold; iii) define the paragenetic sequence of successive gold mineralization events; iv) define vectoring criteria to target gold oreshoots. 

Meliadine vectoring
Muhamad Ilham Hamadi – PhD 
Orogenic gold deposits along the Pyke Fault (Nunavut) consist of arsenopyrite-rich replacement of BIF with folded and transposed quartz-carbonate veins.

Hope Bay vectoring
Angela Rodizes – PhD 
The Hope Bay greenstone belt (Nunavut) hosts orogenic gold deposits where quartz-carbonate-tourmaline veins and replacement mineralization are associated with shear zones and folds formed during dominant D2 deformation.

Ormaque vectoring
Valentin Drouillot – PhD 
This orogenic gold deposit (Val-d’Or) is a typical example of a set of shear zones and extensive sub-horizontal quartz-tourmaline-carbonate veins principally hosted in a porphyry intruded in volcanic rocks, but with a geometry different from that of Triangle, currently under investigation.

Nunavik IM case study – Indicator mineral provenance in regional surveys
(Recruitment underway) 
This case study will integrate the indicator mineral fingerprinting methodologies developed by the previous and proposed research programs in a large regional survey in Nunavik (northern Québec) carried out by the MERN.
Objectives: i) measure the abundance of indicator minerals (scheelite, tourmaline, gold, chalcopyrite, arsenopyrite) in till; ii) measure the major and trace element composition of indicator minerals; iii) assess the provenance of indicator minerals using previous studies fingerprinting criteria; iv) identify deposit types eroded and dispersed in glacial sediments. 

Upper Beaver case study
Julia Biron – MSc 
Upper Beaver is an unusual Cu-Au deposit in the Abitibi (Larder Lake, Ontario), in which the Cu-Au mineralization associated to abundant magnetite is reminiscent of Iron-Oxide-Copper-Gold (IOCG) deposits, unlike typical orogenic gold deposits. It is currently the subject of an integrated study of its geology, intrusion petrology, paragenesis, and hydrothermal evolution by a team from Laval (Beaudoin, Dupuis, Guilmette, LaFlamme, Rottier) and Laurentian (Lafrance, Kontak, Sherlock, Smith). Its unusual characteristics make its signature difficult to recognize in overburden sediments.
Objectives: i) measure the major and trace element composition of potential indicator minerals (gold, chalcopyrite, magnetite, scheelite) in mineralization; ii) compare composition to other potential sources from literature; iii) compare the composition of indicator minerals in mineralization to that in overburden till. 

     Field-based methodologies

Portable LIBS
Emmanuel Traoré – MSc 
Portable Laser Induced Breakdown Spectroscopy (pLIBS) is a relatively new instrument with several analytical advantages over pXRF instruments, including full chemical composition analysis and high sensitivity for precious metals such as gold. Thus, application of pLIBS for major and minor element analysis on drill cores, outcrops, and overburden sediments in deposit-scale and regional exploration has the potential to provide rapid (several acquisitions per second) and high-quality results for quick decision-making in the field.
Objectives: i) measure the chemical composition of rocks and overburden sediments using pLIBS; ii) compare lithogeochemical analyses with pLIBS results; iii) conduct case studies on outcrops, drill core, and overburden samples. 

SWIR case study
Lidbert Alarcón Laime – PhD
This study will field test application of portable Short Wave InfraRed (pSWIR) for detection of gold fertile alteration in both granodioritic rocks of the Bourlamaque batholith and in mafic to felsic volcanic rocks of the Bonnefond corridor, which also host volcanogenic massive sulfide (VMS) deposits and related alteration zones, building on the alteration facies SWIR spectra database of Eldorado Gold (Québec) Inc. The pSWIR instrument has seen wide adoption for mapping alteration in epithermal and porphyry systems, but less so in exploration for orogenic gold despite promising results obtained by the CMIC-Footprint team at Canadian Malartic (Lypaczewski et al., 2019).
Objectives: i) measure SWIR absorption spectra in alteration zones related to gold mineralization, in areas devoid of gold, and VMS alteration zones, in the field and drill core samples; ii) compare the chemical composition of micas and other alteration mineral to their absorption spectra to identify gold-related alteration; iii) relate the SWIR spectra to geological context (metamorphic, versus hydrothermal VMS or orogenic gold); iv) carry case studies on outcrops and drill core.