Crystal Laflamme

• PhD
• Professor (Associate) at Université Laval

Newfoundland is an emerging gold district containing numerous gold occurrences, including past-producers, known deposits with resource estimates as well as a number of advanced exploration projects. This contribution focusses on six gold deposits in southern and central Newfoundland, presenting detailed geological and petrographic descriptions of g...

Amorphous carbon (C(am)) and metallic nanoparticle formation in orogenic gold systems have recently been associated with a sequence of fluid decompression and cooling steps. Nevertheless, C(am) phases and nanoparticles identified in orogenic gold systems remain poorly documented in economic gold veins. Here, we investigate two hydrothermal events,...

The Neoarchean Era is a key period in Earth's history as it witnessed a significant pulse of crustal formation corresponding to the assembly of several cratons, potentially coeval with a transition in the global tectonic regime. Neoarchean metasedimentary subprovinces of the Superior Craton, the largest unreworked Archean craton on Earth, were form...

The Augmitto-Bouzan deposit is a 12 km long segment of the Larder Lake-Cadillac Deformation Zone (LLCDz) south of Rouyn-Noranda (Québec, Canada) that is characterized by an uneven gold distribution hosted in quartz-carbonate ± tourmaline veins within Piché Group ultramafic rocks. This study compares the fluid flow conditions between the variable go...

Paleogeographic reconstructions of ancient orogenic belts, such as the Paleoproterozoic Trans-Hudson orogen (THO), are crucial for understanding of their tectonic evolution and the recognition of potentially different terranes juxtaposed during convergence. The foreland of the Ungava Orogen (UO, Nunavik, Quebec), a branch of the THO, is characteriz...

The Val-d’Or vein field (VVF), located in the southern Abitibi subprovince (Québec, Canada), is host to ~ 47 Moz gold and is therefore an example of a greenstone-hosted orogenic gold district. Gold is contained in quartz-tourmaline-carbonate veins that cut As-poor intermediate to mafic volcanic and intrusive rocks, including dioritic, granodioritic...

Jiama is the largest porphyry-skarn ore system in the Gangdese metallogenic belt, Tibet. It is composed of porphyry Cu-Mo, Cu-polymetallic skarn, Cu-Pb-Zn manto, and distal vein Au orebodies with associated Ag, W, and Bi. However, the precise timing of the magmatism and hydrothermal events at Jiama remains obscure. Here, using high-precision chemic...

Volcanic-hosted massive sulfide (VHMS) deposits, the ancient analogues of “black smoker” deposits that currently form on the seafloor, are the products of complex mineral systems involving the interaction of seawater with the underlying volcanic pile and associated magmatic intrusions. Light stable isotopes, particularly those of oxygen, hydrogen a...

Orogenic gold deposits account for more than 30 % of the global gold resources. To understand the genesis of orogenic gold deposits and ultimately target new orogenic gold deposits, it is important to determine the origin of gold. However, there has been a continuing debate surrounding gold source reservoirs. The Jiaodong gold province, comprising...

The Ungava Orogen (Nunavik, Quebec) has been interpreted as the result of a Paleoproterozoic arc-continent collision, but its magmatic and tectono-metamorphic evolution, as well as its detailed stratigraphy, remain loosely constrained. The Ungava Orogen (UO) is located in the north-eastern portion of the Trans-Hudson Orogen and formed in response...

In orogenic gold deposits, the mechanism by which a hydrothermal fluid precipitates gold in laminated quartz veins remains elusive. The Kanowna Belle deposit hosts gold mineralization in structurally controlled quartz-pyrite laminated veins that cut volcano-sedimentary and granitic rocks of the Kalgoorlie terrane, Australia. Veins show microtextura...

Despite a well-developed structural framework, orogenic gold deposits from the Malartic-Val-d’Or Camp (MVC) report ages that span nearly 345 million years (~ 2705–2360 Ma), significantly post-dating the tectono-metamorphic history of the Abitibi-Wawa Orogeny, and are in conflict with the structural setting along the retrograde path of the orogenic...

Sulfur isotopes ratios (33S/32S, 34S/32S, 36S/32S) are essential for understanding the formation of mineral deposits, as sulfur is the main complexing ligand for gold transport and/or causes metal precipitation (e.g., Cu, Ni, Co, Zn, Pb). Studying sulfur isotopes allow to constrain the source and to monitor the variation on the redox and temperatur...

The source of sulfur in Volcanogenic Massive Sulfide (VMS) deposits is known to be mainly derived from magmatic sulfur mixed with other sulfur reservoirs including seawater sulfate and sulfur from the surrounding country rocks. Seawater sulfate can be incorporated into the circulating hydrothermal fluid by Thermochemical Sulfate Reduction (TSR) and...

Newfoundland is a major emerging gold district containing numerous gold occurrences associated with Paleozoic crustal-scale fault systems. These include the Valentine Lake (3.14 Moz Au measured and indicated resource) and Cape Ray (0.84 Moz Au measured and indicated resource) gold deposits, as well as numerous recent discoveries along the northern...

The Kanowna Belle deposit is a world-class Archean orogenic gold system that witnessed multiple fluid episodes over a protracted deformation history. The hydrothermal fluid circulation episodes at the Kanowna Belle deposit initiated with the precipitation of early gold-bearing carbonate-famatinite-pyrite-telluride-electrum veins (V1a). These early...

Although forming one unified class, orogenic gold deposits may be associated with a range of ore mineral assemblages that are controlled by a variety of gold deposition processes that have direct impacton the associated ore grade. Whereas, a better understanding of the deposition process may be critical for effective targeting of highly-endowed gol...

The Proterozoic rock record displays secular change from ferruginous to an oxic hydrosphere over the course of 2 billion years; however, debate continues on the periodicity, rate of change and steps in following atmospheric oxygenation that ultimately led to an oxygenated ocean. This is partly due to poor preservation of the Paleoproterozoic marine...

Gravity and 3D modelling combined with geochemical analysis examine the subsurface within and below the poorly exposed Palaeoproterozoic Yerrida Basin in central Western Australia. Understanding the structure of a region is important as key features indicating past geodynamic processes and tectonic activity can be revealed. However, in stable, post...

We investigate the relative and absolute timing associated with the formation of the world-class Dead Bullock Soak (DBS) mining camp. The study area is situated in the Paleoproterozoic Granites-Tanami Gold Province in the Northern Territory, Australia, and consists of five orogenic gold deposits, including the Callie deposit with a resource of 14.2...

The Golden Mile and Mount Charlotte deposits in the Kalgoorlie Terrane, Western Australia, display three main mineralization styles: Fimiston, comprised of interconnected shear zones associated with ankerite-pyrite ± hematite- ± magnetite-gold-telluride alteration; Oroya, made up of breccia bodies with V-muscovite-ankerite-pyrite ± pyrrhotite-gold-...

Orogenic gold deposits are commonly associated with a small alteration and geochemical footprint that often hinders the exploration process. In the Granites-Tanami Gold Province; however, we demonstrate that sulfur isotope analysis represent a powerful exploration tool for orogenic gold mineralization. The Granites-Tanami Gold Province, situated in...

The Black Swan Succession consists of an Archean bimodal dacite-komatiite association largely dominated by ultramafic cumulates hosting a number of massive and disseminated magmatic sulfide orebodies. Although it was affected by multiple alteration events, the low degree of penetrative deformation allowed the preservation of magmatic textures and s...

Abstract. Gravity and three-dimensional modelling combined with geochemical analysis are used to examine the subsurface within, and below the poorly exposed Paleoproterozoic Yerrida Basin in central Western Australia. Understanding the structure of a region is important as key features indicating past geodynamic processes and tectonic activity can...

The Savannah (formerly Sally Malay) Ni-Cu-Co Camp is composed of a group of mineralised intrusions (Savannah and Savannah North) and petrologically similar mafic-ultramafic intrusions without known mineralisation (Sub-chamber D, Dave Hill, and Wilson’s Creek). The results of a wide range of analytical techniques (geochemical, geochronological and g...

The Proterozoic Bryah and Yerrida basins of Western Australia contain important base and precious metal deposits. Here we present microtextural data, trace element and S isotope analyses of massive sulphide mineralisation hosted in Palaeoproterozoic subvolcanic rocks (dolerite) recently discovered at Red Bore. The small-scale high-grade mineralisat...

The sulfur cycle across the lithosphere and the role of this volatile element in the metasomatism of the mantle at ancient cratonic boundaries are poorly constrained. We address these knowledge gaps by tracking the journey of sulfur in the assembly of a Proterozoic supercontinent using mass independent isotope fractionation (MIF-S) as an indelible...

Modern seafloor hydrothermal systems are unique environments in which many of the Earth's reservoirs, including the hydrosphere, biosphere, and geosphere, dynamically interact. Analysis of spatially constrained sulfur isotope compositions from fluids and hydrothermal precipitates within the discharge zone of a volcanogenic system can be used to tra...

The Nimbus Ag-Zn-(Au) volcanic-hosted massive sulfide (VHMS) deposit represents an exceptional orebody in the Yilgarn Craton of Western Australia. It is located in a zone of juvenile crust running N-S through the Eastern Goldfields Superterrane. However, unlike most other VHMS occurrences associated with the 2690–2680 Ma rift sequence (Teutonic Bor...

As sulfur is the primary complexing ligand for gold transport in aqueous fluids, recent work has demonstrated that the Archean systems can preserve mass independent fractionation of sulfur (MIF-S) to yield near-zero values (Δ³³S1 = 0 ± 0.5‰). In such cases, interpretation of the geological significance of such isotopic signatures may be compromised...

The Archean orogenic gold deposits exhibits common characteristics including coeval emplacement age often proposed to be associated with a single late tectonic gold mineralisation event. Although valid for a large majority of deposits in the Yilgarn Craton, this model does not account for certain atypical gold deposits. In the world-class Agnew Dis...

Extensional episodes in Precambrian orogens are often difficult to decipher because of subsequent orogenesis and intracontinental reworking. Here, we use geochemical and geochronological constraints of a suite of preserved mafic–ultramafic rocks in the Paleoproterozoic Capricorn Orogen of Western Australia to reveal ophiolites, continental ribbons...

The evolution of a gold-bearing hydrothermal fluid from its source to the locus of gold deposition is complex as it experiences rapid changes in thermochemical conditions during ascent through the crust. Although it is well established that orogenic gold deposits are generated during time periods of abundant crustal growth and/or reworking, the sou...

Mafic and ultramafic magmas that intrude into the lower crust can preserve evidence for metal and sulfur transfer from the lithospheric mantle into the lower continental crust. Here we focus on a series of ultramafic, alkaline pipes in the Ivrea Zone (NW Italy), which exposes deeply buried (6–11 kbar), migmatitic metasedimentary rocks intruded by v...

Determining the source of sulfur in an ore deposit is key to understanding the nature of the ore forming processes. The Neoarchaean Paulsens sediment-hosted gold deposit (∼1 Moz @ 7.6 g/t) located in the Pilbara Craton of Western Australia exhibits many of the characteristics of Phanerozoic shale hosted gold deposits (e.g. Huijiabao Trend, Northern...

The origin of sulfur and gold in Archean orogenic gold systems should provide significant insights into the dynamics of fluid movement in the crust of the early Earth, but is poorly constrained and highly debated. Our natural laboratory to address this knowledge gap is the metal-endowed Yilgarn Craton (Western Australia), where we measured the mult...

The cycle of sulfur, an important volatile in Earth's crust, is the driver of many significant processes such as biological evolution, climate change, and the formation of ore deposits. This study investigates the ancient cycle of volatiles by tracing the indelible signal of anomalous sulfur isotopes, expressed as Δ³³≠ 0, to illuminate the pathway...

Under rare conditions, reworked cratons and their margins preserve the orogenic roots of ancient mountain-building events. However, based on the preservation of high-temperature (~ 800 °C), middle and lower crustal metamorphic assemblages, present day exposure of these terrains is not simply a result of protracted denudation, but also must reflect...

With growing interest in the application of in situ multiple sulfur isotope analysis to a variety of mineral systems, we report here the development of a suite of sulfur isotope standards for distribution relevant to magmatic, magmatic-hydrothermal, and hydrothermal ore systems. These materials include Sierra pyrite (FeS2), Nifty-b chalcopyrite (Cu...

Modern seafloor hydrothermal systems provide important insights into the formation and discovery of ancient volcanic-hosted massive sulfide (VHMS) deposits. In 2010, Integrated Ocean Drilling Program (IODP) Expedition 331 drilled five sites in the Iheya North hydrothermal field in the middle Okinawa Trough, back-arc basin, Japan. Hydrothermal alter...

A preliminary version of this map was published in a page-size form together with a Current Research report, and as a 1:50,000 preliminary geological map based on data collected during the 2008 field season (see Hinchey and LaFlamme, 2009a and 2009b). The current map includes additional data collected during field visits in 2009 and 2010 by the a...

The Repulse Bay block (RBb) of the southern Melville Peninsula, Nunavut, lies within the Rae craton and exposes a large (50,000 km2) area of middle to lower crust. The block is composed of ca. 2.86 Ga and 2.73-2.71 Ga tonalite-trondhjemitegranodiorite (TTG) and granitic gneiss that was derived from an older 3.25 and 3.10 Ga crustal substrate. This...

The Repulse Bay block (RBb) of the southern Melville Peninsula, Nunavut, lies within the Rae craton and exposes a large (50,000 km2) area of middle to lower crust. The block is composed of ca. 2.86 Ga and 2.73–2.71 Ga tonalite-trondhjemitegranodiorite (TTG) and granitic gneiss that was derived from an older 3.25 and 3.10 Ga crustal substrate. This...

The Rae craton on Melville Peninsula, Nunavut, comprises several lithotectonic domains, including a structurally and lithologically distinct yet poorly known crustal terrane, the Repulse Bay block (RBb). This study presents new lithological and petrographic observations, combined with U–Pb zircon data, to better understand the Archean and Paleoprot...

Combined in situ U-Pb and Lu-Hf isotope, and REE analyses of zircons from the tonalite-trondhjemite-granodiorite (TTG)-type gneisses and granitoids within the Repulse Bay block (RBb) of Melville Peninsula, Nunavut, reveal that the block is composed of ca. 2.86 Ga and 2.73–2.71 Ga granitoids that formed by reworking of a 3.25–3.10 Ga basaltic crust....

U–Pb zircon SHRIMP geochronology and Lu–Hf zircon LA–MC–ICPMS isotope geochemistry are used to constrain the ages of Paleoproterozoic felsic magmatism and their crustal sources in the Aillik Group, Makkovik Province of Labrador. This information is important for understanding the extent of crustal reworking vs. juvenile crustal growth in subduction...

Detailed 1:10 000-scale mapping within the Aillik domain of the Makkovik Province has defined the rock types and structural evolution of two areas within the Aillik Group. The Aillik domain is composed of the Aillik Group, a sequence of Paleo-proterozoic volcano-sedimentary rocks, which has been intruded by various Paleoproterozoic intrusive suites...

In The study area lies within the Central Mineral Belt of Labrador, an area that has been previously known to host an abundance of base-metal and uraniferous mineral occurrences. Several mineral occurrences (not recorded in Mineral Occurrence Data System) were documented as a result of this study, aiding to further illustrate the economic potential...