Brigitte Gélinas MSc thesis abstract

Thesis Title: 
Geology and Geochemistry of the Laird Lake Property and Associated Gold Mineralization, Red Lake Greenstone Belt, Northwestern Ontario
Brigitte Rachel
Gélinas
MSc
2018

The Laird Lake property encompasses the tectonic contact between the Balmer (2.99 to 2.96 Ga) and the Confederation (2.74 to 2.73 Ga) assemblages on the south-western end of the Red Lake greenstone belt, Northwestern Ontario. The purpose of this study was to determine the tectonic setting in which the assemblages formed, and to characterize the controls on and nature of the gold mineralization associated with the tectonic contact between the Balmer and Confederation assemblages.

Detailed mapping of the area highlighted major differences between the two assemblages. The Balmer assemblage is typically composed of fine-grained, aphyric, locally pillowed mafic volcanic rocks, ultramafic intrusive and volcanic rocks with flow-breccia textures and local spinifex-bearing clasts, and banded-iron formations. In contrast, the Confederation assemblage consists of porphyritic (feldspar) or poikiloblastic (amphibole) mafic volcanic rocks intercalated with intermediate to felsic volcanic rocks that include crystal lapilli tuffs, crystal tuffs and tuffs. Syn-volcanic and syn- to post-D2 intrusions commonly cross-cut the volcanic packages. A regional foliation (~E-trending) is present throughout the volcanic rocks and increases in intensity at the tectonic contact between the two assemblages where a shear zone no thicker than 100 m is present within the Balmer assemblage.

Whole-rock geochemical analyses were undertaken on 161 samples from the Laird Lake area. The Balmer assemblage is composed of tholeiitic mafic volcanic rocks with minor Al-undepleted komatiites, whereas the Confederation assemblage is composed of calc-alkalic mafic and intermediate to felsic volcanic rocks, which display FI, FII, and FIIIb rhyolite trends. Neodymium isotope analyses, in conjunction with trace element geochemistry, suggests that parts of the Balmer assemblage were weakly contaminated by an older intermediate basement. The data suggests both arc and back arc volcanism within the Confederation assemblage, with the arc rocks showing stronger a crustal component than the back arc rocks. U-Pb geochronology of volcanic and intrusive Confederation units yielded ages of 2741 ± 19 Ma (FI quartz-feldspar porphyritic crystal tuff) and 2737.68 ± 0.79 Ma (diorite). The geochemistry and age of the tuff correlates within error to the Heyson sequence of the Confederation, whereas the diorite is likely a syn-volcanic intrusion.

The Balmer assemblage is interpreted to represent an oceanic plateau formed by plume magmatism on the margins of the North Caribou Terrane whereas the Confederation assemblage was likely built in an oceanic arc setting where both arc and back arc volcanism were occuring simultaneously. The presence of xenocrystic zircons within the 2741 Ma quartz-feldspar porphyritic crystal tuff suggest that melts within the main arc incorporated xenocrystic zircons during ascent through a thin Mesoarchean crustal fragment. Juxtaposition of the Confederation assemblage onto the Mesoarchean assemblages likely occurred between 2739-2733 Ma.

Gold mineralization at the Laird Lake property is controlled by a D2 shear zone within the Balmer assemblage at the tectonic contact between the Balmer and Confederation assemblages. The mineralization is commonly found associated with a mineral banded texture, accompanied by disseminated arsenopyrite, pyrrhotite, pyrite ± chalcopyrite, similar to the features observed at the nearby Madsen gold mine. Oxygen isotope data from early- to syn-D2 gold-mineralized and barren quartz veins suggest both vein types originated from a similar source and overlap with δ18OH2O values of metamorphic, magmatic and meteoric waters, over crystallizing temperatures ranging from 300 to 500°C. Evidence for a second gold event (post-2702 ± 1 Ma) is characterized by the presence of gold-rich shears and lamprophyres cross-cutting the regional foliation, and the lack of overprinting amphibolite facies mineralogy. The Laird Lake property likely represents the continuation of the same mineralized structure found at both the Madsen and Starrat-Olsen mines and was later displaced as far as 10 km west by the dextral Laird Lake fault post-2704 Ma. 

URI
http://knowledgecommons.lakeheadu.ca/handle/2453/4301

Sheree Laina Kirsten Hinz MSc thesis abstract

Thesis Title: 
Geochemistry and Petrography of the Ultramafic Metavolcanic Rocks in the Eastern Portion of the Shebandowan Greenstone Belt, Northwestern Ontario
Sheree Laina Kirsten
Hinz
MSc
2018

The 2.7 Ga Shebandowan greenstone belt in the Wawa-Abitibi terrane contains unusual ultramafic rocks. The two main assemblages present within the study area are the Greenwater and Shebandowan assemblages. The 2719.7 ± 1.0 Ma Greenwater assemblage is characterized by tholeiitic magmatism whereas the 2690-2680 Ma Shebandowan assemblage is characterized by calc-alkalic magmatism. Mapping of a 16 km2 area and 7 trenches has identified the following lithologies in the field area: orthocumulate ultramafic rocks, komatiites, pyroxenite, vesicular komatiites, serpentinite, ultramafic breccia, variolitic ultramafic rocks, mafic intrusive rocks, intermediate intrusive and extrusive rocks, felsic volcaniclastic rocks, monzonite, conglomerate, banded iron formation, argillite and chert. 

The ultramafic rocks are dark black in colour, but light green on surface as a product of serpentine alteration of olivine. They are highly magnetic, with magnetic susceptibility readings from 20 to 150 x10-3 SI. In some areas they occur as fine-grained, massive rocks with no distinct textures, and they also occur as medium-grained dark black rocks with a cumulate texture. The komatiites occur as fine-grained, light grey, highly silicified rocks. Several types of spinifex texture were observed throughout the field area, including: thin chaotic spinifex, thick chaotic spinifex, oriented spinifex, and pyroxene spinifex. Mafic intrusive rocks are massive, medium-grained, equigranular grey-blue gabbro with weakly disseminated pyrite. The intermediate intrusive rocks consist of a fine-grained, green-grey matrix with hornblende phenocrysts and red-pink autoliths. The intermediate extrusive rocks are fine-grained, light grey-blue metavolcanic rocks with medium-grained plagioclase phenocrysts. Felsic rocks in the field area are very fine-grained, light grey, siliceous rocks. They are massive with no flow textures observed in any of the outcrops and the weathered surfaces range in colour from beige to blue-grey.  A monzonite dyke occurs alongside an interpreted fault through the field area. The distinctly magnetic rock consists of a fine-grained, green-grey matrix with hornblende phenocrysts and red-pink autoliths. The conglomerate is a heterolithic pebble to boulder conglomerate consisting of a fine-grained matrix with clasts of basalt, monzonite, and jasper ranging in size from ~2 cm to 40 cm. The argillite is a very fine-grained dark black mudstone. It typically showed no bedding and locally contains graphite and abundant radial pyrite concretions up to 5cm in diameter. It is seen in the trenches intercalated with the hypabyssal komatiitic intrusions. 

The komatiitic rocks have SiO2 values of 47-67 wt. % and MgO values of 2-17 wt. %. Despite being outside the accepted values for komatiites, these rocks were identified as komatiites based on spinifex texture and spatial association with other ultramafic units. The abnormally high silica content in the ultramafic rocks was determined to be caused by silica alteration, and was not a primary feature of the rocks when they were emplaced. The rocks in the field area have undergone silica and carbonate alteration as well as greenschist facies metamorphism.

The Al2O3/TiO2 ratios of the ultramafic rocks are 17-29, and the CaO/Al2O3 ratios of the ultramafic rocks are 2-2.5. These ratios, combined with a flat pattern on a primitive mantle normalized multi-element diagram, identify the rocks as aluminium-undepleted komatiites. A distinct negative Nb anomaly is present in all samples, which could be caused by either the melt being derived from a heterogeneous deep-mantle source, where perovskite fractionation depleted the Nb, or crustal contamination. Sm-Nd isotope analysis was completed on six ultramafic samples from the field area. The εNd of all samples ranged from +2.34 to +2.83, which is not consistent with contamination by older continental crust. Consequently, melting of a heterogeneous deep mantle source is the favoured model for petrogenesis of the ultramafic rocks.

Based on the close spatial association of tholeiitic and calc-alkalic rocks as well as the presence of thick sequences of deep-ocean argillites, the geological environment was determined to be an oceanic-rifted arc through which a plume of heterogeneous deep-mantle melts ascended, that subsequently closed and then collided with the Superior Province. 

 

URI
http://knowledgecommons.lakeheadu.ca/handle/2453/4289

 

 

Kira Arnold MSc thesis abstract

Thesis Title: 
Geology and Geochemistry of the Terrace Bay Batholith, N. Ontario
Kira
Arnold
MSc
2019

The Terrace Bay Batholith is a 25 km long oval shaped granitoid intrusion located in the western portion of the Schreiber-Hemlo greenstone belt, part of the larger Wawa-Abitibi terrane. The pluton was emplaced at 2689±1.1 Ma and intrudes circa 2720 Ma metavolcanic rocks of the Schreiber assemblage. The purpose of this study was to classify the Terrace Bay Batholith petrographically and geochemically in order to investigate the petrogenesis and tectonic setting in which the pluton formed, and to characterize the association with gold and base metal mineralization.

Detailed mapping of the pluton can separate the pluton into three mineralogically distinct lithologies:  granodiorite (typically consisting of medium to coarse quartz and feldspar phenocrysts with a groundmass of fine-grained amphibole, biotite,  disseminated magnetite, and sulphide minerals), a monzogranite (composed of medium-grained quartz and feldspar with increased amounts of potassium feldspar and amphibole relative to the granodiorite), and a diorite (composed of medium-grained amphibole and plagioclase with little to no quartz or potassium feldspar present). Two types of hydrothermal alteration are present in the pluton: a chlorite- epidote and a pervasive hematite alteration. These are present across the pluton, and always in proximity to cross-cutting regional scale faults or shears; however, no association was found between gold mineralization and regional structures.

Whole-rock geochemical analyses were undertaken on 147 samples from the Terrace Bay Batholith. Geochemically, the pluton is a homogenous calc-alkaline pluton, with minimal geochemical change between lithologies. The pluton exhibits trace element signatures that are characteristically arc-related signatures: fractionated heavy rare earth elements, negative high field strength element anomalies, enrichment of Th over light rare earth elements and enrichment of light rare earth elements. The fractionated heavy rare earth elements and the Th-Nb-La systematics are consistent with formation in a subduction zone at depths where garnet is stable. The Sr/Y and La/Yb signatures support formation within the garnet stability field and suggest small amount of slab-derived melt incorporated into the mantle wedge. The isotopic signature suggests that the pluton underwent minimal crustal contamination as shown by the depleted primitive mantle εNd values ranging from +2.16 to +2.49.

The emplacement of the pluton was determined to be through multiple injections in the intrusion from a single source. The pluton underwent prolonged fractional crystallization, creating subtle mineralogical lithologies with no geochemical differences. The homogeneous nature of the pluton suggests it is unlikely that there were numerous pulses because these would result in more variation across the pluton. 

Rhenium-Osmium isotope data were obtained on molybdenite to obtain an age of mineralization for the pluton, yielding a value of 2671±12 Ma. The molybdenum mineralization is spatially associated with gold mineralization in the pluton, suggesting that they were deposited from the same hydrothermal event. As is common in Archean cratons, this age of mineralization is syn- to post- both D2 and regional metamorphism, as well as postdating the emplacement of the pluton. The gold and molybdenum mineralization in the pluton is generally disseminated throughout with local occurrences hosted in quartz veins. Although these exhibit elevated gold and molybdenum values there is no distinct mineralization style characterized with gold deposits. These features can be explained by the magmatic vapor-dispersed system theory which suggests that when a pluton is emplaced at depth, the aqueous phase will remain dispersed throughout the pluton instead of concentrating in economic amounts.

 

URI
http://knowledgecommons.lakeheadu.ca/handle/2453/4542

Munira Afroz MSc thesis abstract

Thesis Title: 
Sedimentology and Geochemistry of the 2.93 Ga Basinal Facies of the Red Lake Carbonate Platform
Munira
Afroz
MSc
2019

The Mesoarchean Red Lake carbonate platform is the oldest (~2.93 Ga) known carbonate platform on Earth.  It is comprised of a variety of chemical sedimentary rocks including: limestone, dolostone, chert, oxide iron formation, and sulfide iron formation.  This study deals with its five different types of deeper water lithofacies, including four chemical sedimentary rocks and siliciclastic black slate, to delineate Mesoarchean ocean chemistry and comprehend the localized depositional settings.  Geochemical analysis of selected elements in the chemical sediments were used to constrain depositional processes.  Of these positive Eu anomalies in REE patterns suggests that the ocean was heavily influenced by hydrothermal activity and positive Ce anomalies in oxide iron formation indicate that a redoxcline existed in the depositional environment. Zirconium and hafnium in oxide facies iron formation were mostly derived from seawater, and their sorption was dependent on the rate of precipitation of iron hydroxide. Multiple sulfur isotope analyses revealed that mass-independent fractionation of sulfur was operating along with bacterial sulfate reduction, and the source of sulfur was diverse.  Organic carbon isotopes increase from ~ -27 ‰ to ~ -20 ‰ up-section towards the shallow portion of the carbonate shelf, possibly reflecting the presence of anoxic phototrophs in the shallows. Inorganic carbon isotopic ratios averaging ~ -1.5 ‰ fall within the range of Archean carbonate and reflect seawater values.  Also, δ18O data reveals that dolomitization occurred in a freshwater influenced environment. Evidence such as increasing Mn concentration towards the carbonate platform and positive Ce anomaly in oxide iron formation, as well as redox-sensitive element enrichment in the chemical sedimentary rocks, suggests that bacterial O2 production was somewhat active in the Mesoarchean sea. The interlayering of various types of chemical sediments at differing stratigraphic scales indicates that localized ocean chemistry changed repeatedly over both short and long time intervals.  Carbonates were perhaps formed in the slightly oxic shallow water environment, while magnetite and chert were precipitated in a suboxic environment distal to any venting fluids and iron sulfides accumulated in a reducing, anoxic environment during intervals of intense venting of hydrothermal fluids.  Shale was deposited as background sediment and accumulated during cessation of chemical sedimentation.  Finally,  the deeper water sediments repeatedly interlayered with the shallow water stromatolitic carbonate successions, which suggests multiple events of carbonate platform flooding.

URI

http://knowledgecommons.lakeheadu.ca/handle/2453/4351

Joseph Vrzovski MSc thesis abstract

Thesis Title: 
Mineral chemistry, hyperspectral analysis and applications for regional exploration at the Hemlo Gold deposit, Ontario, Canada
Joseph
Vrzovski
MSc
2018
The Barrick Gold owned Hemlo Au deposit is a world class Archean Au deposit situated in Northern Ontario, Canada with historic production of >21 Moz of Au over 32 years of continuous operation. The deposit has a strike length of ~3 km with a well-documented alteration footprint surrounding mineralization. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses of epidote, chlorite and pyrite from within and surrounding the Hemlo gold deposit have identified major and trace element variations in mineral chemistry that allow for the discrimination of deposit-proximal and deposit-distal signatures. Short wave infrared (SWIR) analysis of epidote and chlorite from around the Hemlo deposit can discriminate between end-member compositions of epidote and chlorite and is a useful tool for interpreting mineral paragenesis. Epidote varies in chemistry surrounding the deposit with the highest concentrations of As and Sb proximal to the mineralized zones and can be detected at anomalous values up to 1.5 km further than the documented deposit footprint. Using LA-ICP-MS, As and Sb can be detected at significantly higher concentrations (more than an order of magnitude) within epidote than in traditional whole rock geochemistry, allowing for better targeting of the deposit footprint. Chlorite also displayed variation in trace elements with deposit-proximal chlorite displaying exponentially higher Ti/Sr and V/Co values than deposit-distal and intrusion-related chlorite. The Ti/Sr ratio for chlorite expanded the geochemical footprint of the Hemlo deposit by up to 1 km. Pyrite displayed anomalous enrichments in a number of elements, including Au, Ag, As, Sb, Bi, Te, Mo and W, that could be detected at elevated concentrations proximal to the deposit. Gold, Te and As proved to be the most effective pathfinder elements in pyrite as they were detected at anomalous concentrations up to 2.5 km from the deposit and were detectable in pyrite at much greater concentrations relative to whole rock geochemistry. Several syn-to post-tectonic intrusions that surround the deposit were evaluated using epidote and chlorite chemistry for their potential to create false positive anomalies for mineralization. The distal intrusions of interest displayed no distinctive variation in epidote or chlorite chemistry and did not display false positive anomalies. Intrusion related epidote contain consistently low As and Sb levels relative to deposit epidote was also displays elevated Fe/Al values. Intrusion related chlorite displayed low Ti/Sr and V/Co values relative to the deposit chlorite and was also found to be more enriched in Fe relative to deposit-proximal chlorite.

Nicholas Craik HBSc thesis abstract

Thesis Title: 
Exploring the Subaerial Redox Environment of the Mesoproterozoic Copper Harbour Conglomerate, Michigan, USA
Nicholas
Craik
HBSc
2020
 
The Copper Harbour Conglomerate of the Keweenaw Peninsula, Michigan is a fining upward, alluvial-fluvial-lacustrine sedimentary sequence representing the first continuous infilling of the Midcontinent Rift basin after the cessation of associated volcanic activity ~1.1 Ga. Within the formation are pervasive carbonate cement (calcrete) lenses as well as a stromatolitic horizon located within its uppermost portion. The purpose of this study was to examine the oxidative weathering products (siliciclastics), groundwater-precipitated carbonates (calcrete), and fluvial-precipitated carbonates (stromatolites) found within the subaerial Copper Harbour Conglomerate to determine the relative oxygenation of the atmosphere at the time of deposition. Past studies on atmospheric oxygen levels during the Mesoproterozoic commonly utilized deep sea shales with indeterminate and questionable weathering and hydrological pathways. In opposition to this, the Copper Harbour Conglomerate was in direct contact with the atmosphere during deposition (subaerial) and is unmetamorphosed making it a reliable proxy for atmospheric oxygen levels at the time of deposition (~1085 Ma). ICPMS and ICP-AES methods were utilized to determine the geochemistry of the rock types within the upper Copper Harbour Conglomerate. By analyzing the redox sensitive metals and rare earth elements, theoretical constructions of the hydrological pathways of these elements allows the understanding of the redox environment during deposition. Through examination of the oxidative weathering products, groundwater-precipitated carbonates, and the fluvial-precipitated carbonates using redox sensitive metals and rare earth elements, it was determined that atmospheric oxygen levels ~1085 Ma were greater than previously thought.

Khalid Yahia HBSc thesis abstract

Thesis Title: 
Tectonic Investigation on Mackenzie River granites
Khalid
Yahia
HBSc
2019

Mackenzie River granites (MRG), are Archean deformed granites exposed in many locations alongside Highway 11/17 east of Thunder Bay. Microcline and plagioclase are the dominant minerals with quartz that slightly varies in proportion from one location to another. The samples that were examined petrographically are classified as ten granite samples, two granodiorite, one tonalite, and one quartz monzonite. Greenish chlorite was observed in most of the fractures in the study area. Two main populations of fracture strike were recorded in the study area. A NE-SW strike of fractures and faults was the major and dominant strike direction. This direction of strike agrees perfectly with one arm of the Midcontinent Rift (MCR). The second major population of structures strikes NW-SE with fewer fractures compared to the NE-SW strike of structures. The deformation history of MRG is documented by four main deformational features: penetrative brittle-ductile deformation, brittle deformation including a cataclasite-filled fault, chlorite-filled fractures, and quartz-filled fractures. Subgrains, serrated grain-boundaries, and undulose extinction are the main dislocation-creep features in quartz besides the bent and deformed twins of plagioclase and microcline. These dislocation-creep features were observed as evidence of penetrative brittle-ductile deformation at a depth of more than 15km for MRG at the time of deformation. Brittle deformation is indicted by the fractures in MRG and cataclasite-filled fault. Cataclasite-filled fault is identified by its 0.2-0.5mm crushed angular mineral pieces that have the same mineralogy as MRG. Chlorite-filled fractures are Archean, supported by the cross-cutting relations in the field. Quartz-filled fractures are younger than Gunflint Formation (GF) as they are present in (GF).

 

Liam Fay Honours Thesis Abstract

Thesis Title: 
Mineral Chemistry of the Heron Bay Area, Northwestern Ontario
Liam
Fay
HBSc
2017

Heron Bay, Ontario comprises a predominantly calc-alkaline felsic to intermediate subduction-related arc setting of volcanic and plutonic rocks of mostly crystal tuff, tuff and granite. The rocks have undergone amphibolite facies metamorphism and are predominantly schists and gneisses. Trace element concentrations in pyrite, chlorite and epidote are variable. Highest values of Archean Au pathfinder elements, Au, Sb, W, Bi and As in pyrite are observed in pyrite associated with tourmaline in veins and disseminations. Highest concentrations of Au, Sb, W, Bi and As in chlorite and epidote are generally  associated with chlorite and epidote that occurs in veins rather than as major to minor constituents of rocks or as replacements. Trace element abundances in pyrite, chlorite and epidote are similar to Hemlo, the La Colosa Au-porphyry deposit and Gosowong, Toguraci and Penelope epithermal deposit pyrite, chlorite and epidote. Heron Bay chlorite is similar to metamorphic chlorite from Shebandowan and West Scotland and Heron Bay epidote is similar to metamorphic epidote from West Scotland.

No strong trace element trends towards the Heron Bay Au mine are apparent. The lack of strong vectoring trends may be attributed to metamorphic overprint, the small size of the Heron Bay Au system and variability in trace element concentrations among the differing occurrences of pyrite, chlorite and epidote.

Conway Brown HBSc thesis abstract

Thesis Title: 
A Microstructural Analysis of Alto Ventures’ Miner Lake Property
Conway
Brown
HBSc
2020

Alto Ventures’ Miner Lake property is located 55 kilometers northeast of Beardmore, Ontario.  Historically, this property has been prospected for gold, which is Alto’s current target.  For this study two trenches, Trench 35 and the Musketeer trench, were investigated.  The outcrops were divided into five lithozones based upon the intensity of alteration, noticeable fabric, grain-size, strain observable within mineral grains, and strain observable within porphyroclasts. The rock within both trenches is ultramylonitic quartzofeldspathic schist originating from deformation and metamorphism of a plutonic tonalitic protolith.  Ductile deformation is largely homogenous throughout every lithozone, and brittle deformation is only observed within lithozones three, four, and five.  Brittle deformation becomes more pronounced with each increasing lithozone and provides an important route for hydrous fluids to enter the system.  Increasing amounts of fluid are correlated to increasing amounts of alteration minerals, such as chlorite and white micas, and are also correlated to increasing amounts of ductilely deformed quartz veins.  Areas of the trenches that display a higher abundance of deformed quartz veins have typically returned higher gold assay values, providing a possible control on the gold mineralization within the study area.

Therefore, it is suggested that rocks with greater abundances of alteration minerals and deformed quartz veins are better targets for gold mineralization.

Mitchell Marcelissen HBSc thesis abstract

Thesis Title: 
Mineral Chemistry of the Gaspé Porphyry, Gaspé, Québec
Mitchell
Marcelissen
HBSc
2020

The Mines Gaspé property hosts multiple Cu-Mo skarn and porphyry orebodies and is located adjacent to the town of Murdochville in the northeastern part of the Gaspé Peninsula, Québec. Both types of orebodies occur within the zoned Copper Brook and overlapping Porphyry Mountain alteration aureoles in calcareous Lower Devonian sedimentary rocks. The strata are intruded by numerous multiphase porphyry sills, dykes, and plugs of Devonian age. Underground and open pit mining at Mines Gaspé ceased in1999 after 141 Mt of 0.9% Cu-equivalent had been extracted from two open pits and eight underground mining areas within the Copper Mountain and Needle deposits. The Porphyry Mountain deposit is the most promising undeveloped resource on the property, containing 437 Mt of ore at 0.89% Cu-equivalent. The Porphyry Mountain intrusion and a sill in the Copper Mountain pit have been dated at 378.80 ± 0.57 Ma and 377.60 ± 0.62 Ma, which better constrains the timing of intrusions at Mines Gaspé than previous studies. Epidote UPb ages at Mines Gaspé overlap within error from 367–352 Ma. Epidote at Mines Gaspé is ~10 million years younger than the Porphyry Mountain intrusion. The time period between the Porphyry Mountain intrusion and epidote formation, as well as the range in epidote ages suggests that the Mines Gaspé system was active for a protracted period of time and more than one generation of epidote is likely, similar to the multiphase occurrence of intrusive units.

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses 
of epidote and chlorite from within and between the Copper Mountain and Porphyry Mountain deposits have identified major and trace element spatial variations in mineral chemistry. Epidote analyses show the highest values of Mg, U, Zr, Ti/Co, U/Co, Mg/Sb, and Mg/Zn proximal and As, Mn, Sr, Sr/U, As/U distal to the Porphyry Mountain deposit. Chlorite analyses show the highest values of Li, Ti, V, Ti/Co, Ti/Sb, V/Co, and Zn/Mg proximal and Mn, Zn, Zn/Li, and Zn/V distal to the Porphyry Mountain deposit.

Trace element concentrations in epidote and chlorite show a geochemical footprint surrounding the Porphyry Mountain deposit that allows for the use of mineral chemistry as a tool for vectoring towards porphyry-style mineralisation at Mines Gaspé.

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