|
Nemaska Project - Whabouchi |
|
|
Quebec, Canada |
| Main commodities:
Li
|
|
 |
|
|
 |
Super Porphyry Cu and Au
|
IOCG Deposits - 70 papers
|
All papers now Open Access.
Available as Full Text for direct download or on request. |
|
|
The Nemaska Lithium Project, Whabouchi Mine is located in the James Bay area of the Province of Quebec, Canada, ~30 km East of the Cree community of Nemaska and 300 km north-northwest of the town of Chibougamau (#Location: 51° 41' 6"N, 75° 50' 36"W).
The earliest exploration in the area included the discovery of a lithium-bearing pegmatite by the geologists of the Québec Bureau of Mines in 1962, and back-pack drilling of sample holes on the pegmatite by the company Canico in the same year. This was followed by 3 diamond drill holes on the same pegmatite ridge in 1963. No further exploration was undertaken over the next ten years, until James Bay Nickel Ventures (a Canex Placer subsidiary) carried out a large-scale geological reconnaissance for nickel that covered the pegmatite area (Burns, 1973). Between 1974 and 1982, an extensive geochemical survey, followed by geological reconnaissance of anomalies, was performed by the Société de Développement de la Baie James (SDBJ). Two exploration programs, one in 1978 and the other in 1980, targeted lithium, including the evaluation of the Whabouchi spodumene-bearing pegmatite. No channel sampling or drill hole data are recorded. No further work was conducted from 1982 to 1987. In 1987, Westmin Resources completed an airborne Dighem III survey covering an area immediately east of the Whabouchi property. In 1987-88, Muscocho Exploration also completed ground magnetic and VLF surveys that covered a major part of the property. The spodumene-bearing pegmatite gave a weak magnetic and VLF response. Muscocho Exploration was exploring for massive sulphides, with a program of 14 holes, 11 of them drilled on the southern part of the Whabouchi Property.
In 2002, Inco, while exploring for tantalum, resampled the spodumene-bearing pegmatite, taking 11 channel and 7 grab samples, the best of which returned assays of 0.026% Ta, and Li2O values ranging from 0.30 to 3.72%. Inco undertook no further followup work. In the autumn of 2009, Nemaska Lithium Inc. (formerly Nemaska Exploration Inc.), initiated exploration work at Whabouchi, with 9 samples of outcropping spodumene-bearing pegmatite that returned values ranging from 6.3% to 1.18% Li2O. Overburden stripping exposed the spodumene-bearing pegmatites for mapping, followed in 2010 by further drilling, and ground and helicopter borne magnetic data acquisition. In May 2011, a 50 tonne bulk sample was collected at surface for metallurgical testing. A total of 277 diamond drill holes were completed to define the deposit, as well as for geotechnical and metallurgical tests. In 2022, one of the shareholders of Nemaska Lithium, Livent Corporation, bought out all but one of the other partners to increase its share of the company to 50%. The remainder was owned by Investissement Québec, an arm of the Quebec Provincial Government. In December 2023, Livent Corporation and the Australian company Allkem Limited merged to form Arcadium Lithium plc, which as a consequence included the 50% ownership of Nemaska Lithium. In 2024, Rio Tinto acquired Arcadium Lithium and its 50% interest in Nemaska Lithium.
In May 2023, the Ford Motor Company entered into a 11 year supply agreement with Nemaska Lithium, commencing in 2025. The agreement initially calls for spodumene concentrate and a later transition to delivery of battery-grade lithium hydroxide. Spodumene concentrate produced exclusively from the Whabouchi mine will provide the feedstock for lithium hydroxide at volumes of up to 13 000 tonnes per annum, which is equivalent to ~100 000 dry tonnes of spodumene concentrate per annum.
The spodumene concentrate is to be trucked 405 km on an all weather road using b-double trucks to the railyard in Matagami, to be railed 900 km to Bécancour where it will be stored and then to be feed to the Bécancour conversion plant, to produce lithium hydroxide that will be delivered to global markets via the Port of Montréal.
Regional Setting
The Whabouchi deposit pegmatites are located ~200 km ENE of the southern tip of James Bay, in the eastern cratonic Superior Province of the Canadian Shield. They intrude amphibolites, low in the Neoarchaean volcano-sedimentary Lac des Montagnes Group. The latter group, and the overlying meta-sedimentary rocks of the Voirdye Formation, together define the Lac des Montagnes Belt. This belt comprises a narrow thrust bound corridor, interpreted to lie along the southern margin of the La Grande Subprovince of the cratonic Superior Province (Bandyayera et al., 2022). As such it is structurally juxtaposed with largely Mesoproterozoic gneisses of the Opatica Subprovince immediately to the south. To the west, this same belt is in fault contact, both transform and south vergent thrusting, with possibly temporally equivalent, but more strongly metamorphosed, sequences of the Nemiscau Subprovince. Until recently, the Lac des Montagnes Belt Group was considered to be a narrow extension of the metasedimentary Nemiscau Subprovince, connecting it to the similar lithofacies of the Opinaca Subprovince to the east (e.g., Valiquette, 1963, 1975; Card and Poulsen, 1998). More recent mapping (e.g., Bandyayera et al., 2022) has instead assigned it to the La Grande subprovince. That mapping, as illustrated on the Quebec SIGÉOM GIS, indicates both the Lac des Montagnes Group, and the shear zones that bound it and the Lac des Montagnes Belt to the north and south, curve clockwise to the east, to follow the thrusted northern margin of the Opatica Subprovince, as shown on the accompanying regional image. This mapping shows the belt to broaden to the east, before being truncated by a large crosscutting mass of meta-sedimentary to meta-volcanic gneiss, migmatite, granite, tonalite and granodiorite of the Épervanche Complex. This complex separates the belt from the late Mesoproterozoic Grenville Front.
As described above, the Nemiscau and Opinaca sub-provinces are characterised by Archaean meta-sedimentary facies, predominantly medium grained
meta-greywacke and fine-grained metapelite deposited between ~2685 and 2648 Ma (e.g., Moukhsil et al., 2007). These are in contrast to the gneissic volcano-plutonic, tonalite-trondhjemite-granodiorite (TTG) dominated rocks of the La Grande Subprovince to the north and Opatica Subprovince to the south. The volcano-sedimentary Lac des Montagnes Group and overlying Voirdye Formation meta-sedimentary rocks were originally correlated with similar facies of the Nemiscau Subprovince, now mapped as the Peat Formation and Rupert Complex respectively. However, the volcano-plutonic La Grande Subprovince is overlain by remnants of the lithologically similar Eastmain Group to the east and Anatacau-Pivert Formation to the west (also shown as Eastmain Group on the image below), which Bandyayera et al. (2022) suggest may be correlates of the Lac des Montagnes Belt sequence. It is likely all reflect a widespread tectonic regime, elements of which have since been structurally juxtaposed.
Geology
The ~260 km long, by 2 to 8 km wide, ENE trending Lac des Montagnes Belt, which is ~7 km wide in the Whabouchi area, appears to be as much as 20 km wide in the east-west section to the east. The belt is composed of volcano-sedimentary assemblage protoliths that have been metamorphosed to amphibolite facies. It is bounded to the north by the La Grande Subprovince, represented by granitoids of the Mesoarchaean Champion Complex which is overlain by a Neoarchaean volcano-sedimentary sequence, that is, in turn, intruded by further batholiths. To the SE, the Lac des Montagnes Belt is juxtaposed by the Neoarchaean Opatico NE orthogneisses and undifferentiated granitoids. In more detail, these units comprise the following, from north to south; after Bandyayera and Caron-Côté (2018) and the Ministére des Ressources naturelles et des For&eacirc;ts SIGÉOM GIS interactive map (viewed December, 2024):
La Grande Subprovince
The southwestern section of the La Grande Subprovince includes the following elements in the area around the Nemaska Lithium Project
• The Mesoarchaean Champion Complex occupies a NE-SW elongated area of ~200 x 65 km and has been dated at 2843.7 ±5.4 to 2838.1 ±4.7 Ma (U-Pb zircon; David, 2020; Pedreira Perez et al., 2023). It comprises a large multi-phase intrusive mass which includes the following intrusive suites:
i). Light grey, medium grained, tonalitic gneiss that is locally granitic. It is heavily deformed, folded, locally banded, heterogeneous and weakly to highly magnetic. The gneissic texture is primarily marked by alternating millimetric to centimetric ribbons of white and greyish, medium-grained tonalite to diorite. These ribbons contain 10 to 20% greenish hornblende and brownish to greenish-brown biotite in varying proportions. Biotite is chloritised and commonly has zircon inclusions. Accessory minerals are allanite, sphene and apatite. It also includes up to 20% clasts of foliated, to locally gneissic, strips of magnetic diorite that are up to tens of metres thick. The tonalitic gneiss is metaluminous to locally peraluminous, typically calcic and moderately enriched in potassium. This suite forms broad elongate bands, one of the most significant of which is located immediately to the north of, and parallel to the Lac des Montagnes Belt of volcano-sedimentary rocks and is 5 to 10 km wide and 65 km long. A sample of this tonalitic gneiss has been dated at 2816 ±3 Ma (David, 2020), whilst another sample from 1 km to the NE of Spodumene Lake was dated at 2889 ±14 Ma (Bynoe, 2014).
ii). Medium-grained and locally hematised tonalite and pyroxene-hornblende granodiorite. It is pale grey to beige, homogeneous or weakly foliated, has a granoblastic and equigranular texture, and is largely absent from the immediate area around the Nemaska deposit.
iii). Light grey to beige biotite-rich quartz diorite and diorite, which is generally very limited in occurrence, and composed of rocks of mainly intermediate composition with 40 to 60% mafic minerals, mainly hornblende and biotite, and 2% of magnetite. They are metaluminous, of calc-alkaline affinity and characterised by the absence of europium anomalism. These are also largely absent from the Nemaska deposit vicinity;
iv). Medium-grained, homogeneous, weakly to strongly foliated, granoblastic, greyish granodiorite, which is locally tonalitic. It generally contains 10% biotite, 2 to 10% hornblende and 1 to 2% magnetite. The foliated rocks are the richest in mafic minerals, with contents of up to 20% hornblende and biotite. They are borderline metaluminous and are peraluminous, with a calc-alkaline affinity and depleted to moderately enriched in potassium;
v). Pinkish-grey, homogeneous, massive to locally weakly foliated granodiorite, which is distinguished by its porphyritic texture with 2 to 20%, but averaging ~10% x 1 to 2 cm, euhedral, K feldspar phenocrysts. It contains <15% mafic minerals, including 10 to 15% partially chloritised biotite and 1 to 10% hornblende. Sphene, allanite and magnetite are the most common accessories. This suite represents the main central bulk of the Champion Complex; and
vi). A package of brownish beige to light grey, magnetic and hematised granodiorite and granite, characterised by significant quantities of migmatite and tonalitic or granodioritic gneiss enclaves that have been strongly assimilated.
• The early Neoarchaean Eastmain Group, which unconformably overlies the Champion Complex, is extensively preserved 10 to 50 km north of the Lac des Montagnes Belt. However numerous remnants of the lower part of this sequence, particularly the Natel Formation, as described below, are mapped in close proximity to the north of that belt. The lower Eastmain Group incorporates four volcanic cycles. The period from 2752 to 2720 Ma took in stages I and 2, characterised by tholeiitic then komatiitic basaltic magmatism respectively, with a few late andesites and by bimodal mafic and felsic magmatism. These are interpreted to be the product of volcanism associated with ocean floor spreading at mid-ocean ridges and/or oceanic platforms. The third stage, between 2720 and 2705 Ma, involved the eruption of further mafic lavas of tholeiitic affinity, followed by the sporadic eruption of andesites and rhyolites that were emplaced along syn-volcanic faults. The fourth stage, from 2705 to 2697 Ma involved the gradual decline of volcanism and the deposition of pyroclastic rocks from distal centres of subaerial explosive volcanism prior to the main D1 deformation event at <2687 Ma. This was followed by another sedimentation event, characterised by the erosion of volcano-plutonic assemblages to produce coarse clastic sediments, particularly conglomerates. This stage was accompanied by intense plutonic activity associated with the emplacement of syntectonic plutons between 2710 and 2697 Ma which culminated in the emplacement of post-tectonic, generally pegmatic, intrusions. The fifth stage is characterised by the absence of volcanic activity, and the deposition of thicker sequences of greywacke and pelite, which after 2670 Ma, underwent high-temperature, low-pressure metamorphism (Moukhsil et al., 2007). Proximal (within 5 to 20 km) to the Lac des Montagnes Belt, the following units of the Eastmain Group are mapped:
i). Natel Formation, which consists of massive or pillowed flows of amphibolitised tholeiitic and komatiitic basalt, andesite and rhyolite, as well as volcaniclastic units, including block and lapilli tuff and lenticular interlayers of black mudstone and greywacke. The volcanic rocks, which overlap both volcanic cycles 1 and 2, are predominantly of tholeiitic affinity. The main bulk of this unit is ~50 km to the NE of the Whabouchi deposit where it may be up to 2 km thick with a lateral extent of ~100 km, although numerous remnants cap the Champion Complex near the Whabouchi Mine. Age dating of volcanic units suggest it was deposited between 2739 and 2720 Ma (Moukhsil et al., 2003).
ii). Auclair Formation, which is primarily composed of paragneiss after volcanic and volcaniclastic rocks of intermediate to felsic composition. It has been subdivided into the following lithofacies: a). paragneiss after sedimentary protoliths, representing the bulk of the formation; b). oxide facies iron formation; c). andesite, rhyolite, rhyodacite and lapilli and block tuffs; and d). polymictic conglomerate. The degree of metamorphism of these rocks varies from greenschist to upper amphibolite facies. Very little of this formation is found within 50 km of the Whabouchi Mine.
iii). Anatacau-Pivert Formation, which are locally developed, ~10 km north of the Lac des Montagnes Belt and ~45 km to the WSW of the Whabouchi deposit in the western La Grande Subprovince. Here, they comprises amphibolitised, massive to pillowed basalt flows which are locally brecciated, and are usually amygdaloidal, grading to amphibolite. Pillow basalt protoliths represent >60% of unit and have been dated at 2716 Ma, interpreted to represent volcanic cycle 3. These are overlain by more extensive developments of slaty siltstone and mudstone and conglomerates containing up to 55% quartz, 11% plagioclase, 23% biotite and 15% muscovite.
It is suggested (Bandyayera et al., 2022) that the Eastmain Group may be an equivalent of the Lac des Montagnes Belt sequence, which those authors also attribute the La Grande Subprovince, whilst Moukhsil et al., 2007 correlates the thick sedimentary successions of the Nemiscau and Opinaca sub-provinces with the fifth stage of the Eastmain Group, deposited in the two deeper extensional basins straddling the shallower La Grande Subprovince.
• Plutonic intrusions of the La Grande Subprovince. A number of suites of tonalite-trondhjemite-granodiorite (TTG), tonalite-granodiorite-granite-quartz monzonite (TGGM) and tonalite-trondhjemite granodiorite-monzogranite (TTGM) that were emplaced between
2747 and 2697 Ma have been identified, whilst at ~2668 Ma, the late intrusions of granodioritic to granitic composition occurred. These latter intrusions are locally pegmatitic, some of which are spodumene-rich, and cut the Auclair Formation. The principal of these intrusions within the southern La Grande Subprovince include:
i). The Neoarchaean Quindéle Pluton - which is composed of two main packages: a). a suite of medium to coarse-grained biotite tonalite and granodiorite that cannot be mapped separately, and represents >60% of the main pluton. It is homogeneous, foliated, locally gneissic and weakly magnetic; and. b). medium-grained, locally pegmatitic, whitish monzogranite, composed of 30% quartz, 30% microcline, 28% plagioclase and 3 to 5% brownish biotite. Apatite, magnetite and epidote are accessory minerals that make up ~2% of the rock.
The main pluton intrudes both the Eastmain Group and the Champion Complex, and contains kilometre scale enclaves of the Middle Eastmain Gabbro and Diorite unit, whilst it is only in shear contact with the Natel Formation.
ii). The early Neoarchaean Middle Eastmain Gabbro and Diorite - mafic to intermediate intrusions that consist of gabbro, diorite and glomerophyric gabbro. The diorite appears to post-date the gabbro. They have been metamorphosed to amphibolite facies, with hornblende the dominant ferromagnesian mineral. Both the gabbro and diorite are intrusive into the Natel and Auclair formations, and the Quindéle Pluton, despite the latter containing enclaves of these same rocks.
iii). The Neoarchaean Valiquette Pluton - an east west elongated, 100 x 15 to 45 km intrusive mass of homogeneous, massive to very weakly foliated, and locally pegmatitic, medium to coarse-grained biotite granite. It is locally hematised and is typically pink to pale pink, generally containing 1 to 5% biotite, 2% hornblende and 2% magnetite. Biotite is partially to completely chloritised and locally epidotitized. It is peraluminous, calc-alkaline to shoshonitic, potassium-rich, with >4 wt.% K2O, and is characterised by negative Eu anomalies. This intrusion differs from other granitic rocks in the area by its high Rb concentrations. The pluton has been dated at 2708 ±6 (Ackerman et al., 2022), 2704 ±5.3 Ma (Bynoe, 2014).
iv). The Neoarchaean Arques Intrusion - a strongly magnetic polyphase intrusion that includes diorite, monzonite, syenite and gabbro, cut by massive and locally layered intrusions that are hundreds of metres across of pink magnetite-amazonite granitic pegmatite. These pegmatites contain 2 to 5% enclaves of tonalite or tonalitic gneiss and pyroxenite intrusions. A number of intrusions are evident in the district, although the largest is an ellipsoidal, NE-SW oriented, 8.9 x 5.5 km mass was emplaced, overprinting the Rupert River Shear Zone that defines the northern margin of the Lac des Montagnes Belt. It cuts tonalitic gneiss of the Champion Complex to the north, paragneiss of the Voirdye Formation to the south, and late-tectonic intrusions of the Kaupanaukau Suite. The latter intrusion’s margin consists of intrusive breccias cut by numerous intermediate to ultramafic dykes.
v). The late-tectonic Kaupanaukau Suite is a package of granitic intrusions and granitic pegmatite that cut all the other Archaean rocks in the region, including those of the Lac des Montagnes Belt and the Opatica and La Grande subprovinces, including the Champion Complex, Lac des Montagnes Group, Voirdye Formation, Valiquette Pluton, Sicotiére Suite and Théodat Complex. It is composed of three units:
a). Pink biotite ±magnetite granite, which occurs as intrusions with dimensions of from tens of metres to kilometres, within the Champion Complex. It is composed of homogeneous, hetero-granular and low to highly magnetic susceptibility massive granite to locally granodiorite with accessory apatite and zircon.
b). Pink pegmatite and granite, a package of intermixed granitic pegmatite and biotite ±magnetite granite, which are not readily separated in mapping. Grain size contacts are generally gradual and diffuse, from medium and coarse-grained to pegmatitic, and locally sharp, indicating intrusion of pegmatite into granite.
c). Pink granitic pegmatite with a graphic structure. It is magnetic and has a massive and hetero-granular appearance, as well as locally visible banding or pegmatitic zoning. It regularly contains clusters of K feldspar up to 5 cm across that are cemented by quartz. The pegmatite has well-developed graphic and perthitic textures, whilst granitic pegmatite is distinguished by <5% ferromagnesian minerals. It contains no garnet and rarely tourmaline, but encloses enclaves of all other units of the Champion Complex. To the SW of the Whabouchi Mine, an exposure of the pink pegmatite contains up to 20% of paragneiss-derived migmatite enclaves originating from the supracrustal rocks overlying the Lac des Montagnes Group. The various units in the Kaupanaukau Suite are elongated and are up to 15 km long and 2 km wide, although locally, they form small rounded masses ranging from 1.5 to 2 km in diameter. Massive granites and pegmatites of the Kaupanaukau Suite have been dated at 2598.6 ±7.2 Ma (Pedreira Perez et al., 2023).
Riviére Rupert Shear Zone
The Riviére Rupert Shear Zone is a major ENE to NE trending, NW dipping, ~180 km long, regional reverse dextral structure. It marks the boundary between the Lac des Montagnes Belt and the Champion Complex of the main La Grande Subprovince to the north. It is marked by numerous corridors of extreme deformation, from metres to tens of metres in thickness, affecting all units of the Lac des Montagnes Group and overlying Voirdye Formation (and Rupert Complex to the west), Champion Complex and Valiquette Pluton. Within these deformation corridors, the original rock is generally unrecognisable or difficult to identify. Foliation is usually mylonitic and has a strong stretching lineation, of variable orientation, but with a dip generally between 40 and 60°E.
Lac des Montagnes Belt
The Lac des Montagnes Belt is a corridor that separates the La Grane and Opatica subprovinces to the NW and SE respectively. This corridor is defined by the NW dipping Riviére Rupert Shear Zone to the north, as described above, and the SE dipping Poste Albanel Shear Zone to the south, as described below. It comprises two main suites of volcano-metasedimentary rocks, cut by multiple multi-phase intrusions of felsic to ultramafic composition. It includes the following elements in the area around the Nemaska Lithium Project.
• Mesoarchaen basement Hutte Complex - dated at ~ 2952.2 ±5.4 to 2790.4 ±5.4 Ma (U-Pb zircon; David, 2020; Pedreira Perez
et al., 2023), comprises a package of gneissic plutonic rocks of a generally tonalitic composition, with local granodioritic or granitic varieties. The Complex forms ENE-WSW aligned domes that are 3 to 12 km long x 0.5 to 5 km wide. The complex is made up of three mappable units:
i). Grey tonalitic and locally granitic gneiss, with lesser granodiorite. The unit is weakly to strongly magnetic, with foliated, folded and banded structures. The gneissic banding occurs as ~15% alternating greyish millimetric to centimetric biotite- and hornblende-rich bands with >50% intervening whitish layers of more abundant plagioclase. Banding is locally accentuated by centimetric injections of pink granite or granodiorite aligned parallel to the foliation planes. This unit is the best developed of the three.
ii). Strongly foliated to gneissic biotite ±hornblende tonalite. It is homogeneous, medium grained, light to dark grey, and typically contains 15% biotite, 5% hornblende and traces of magnetite. The unit contains 2 to 5% stretched enclaves of homogeneous, dark grey granoblastic diorite that include 40 to 50% biotite and hornblende, and is cut by several multiphase injections of pegmatitic and massive pink granite.
iii). Light pink, medium to coarse grained and locally pegmatitic, foliated granite containing 3 to 10% biotite and 1 to 3% magnetite.
• The Lac des Montagnes Group which unconformably overlies the Hutte Complex, extends discontinuously over an east-west and then ENE-WSW strike length of ~260 km and is exposed over a width that generally ranges from 200 to 1000 m. Samples from the group have been dated at 2703.6 ±4.9, 2723.2 ±3.9 and 2706.4 ±6.7 Ma (U-Pb zircon; David, 2020). It is composed of five units as follows:
i). Variably metamorphosed basalt, which occurs as massive to pillow flows and flow breccias. These represent a sequence of tholeiitic- and andesitic-basalts of transitional affinity, with rare earth and trace element ratios typical of those of N-MORB origin. They have a fine to very fine grain size and a generally grano- to nemato-blastic microtexture, and are mainly composed of >50% amphibole (hornblende, actinolite-tremolite) and 40% plagioclase, with associated minor quartz and biotite. Hornblende is partially replaced by chlorite and epidote. These rocks are metamorphosed in the range from upper greenschist to amphibolite facies and contain sphene, sulphides, calcite and sericite as accessory or alteration minerals. Locally, they contain layers that are tens of cm thick, composed of fine to medium grained, dark grey to brownish and greenish grey, massive to pillowed, ultramafic lava that are tremolite-rich and magnetic. This unit is the country rock intruded by the main spodumene pegmatite of the Whabouchi Mine.
ii). Intermediate volcanic rocks, which lithogeochemical analyses suggest are meta-andesites of calc-alkaline affinity. They contain 60% x 0.5 to 5 mm hornblende and 1% to 2% x 0.2 to 0.5 mm magnetite, and are richer in SiO2, TiO2 and light rare earth elements than the basalt unit. They are the least encountered unit in the group.
iii). Felsic volcano-clastics, interstratified with meta-basalts of the first unit. The best preserved lithologies are lapilli and ash tuffs that are tens to hundreds of metres in thickness. Lithogeochemical analyses indicate these are of rhyodacitic composition and calc-alkaline affinity, and are significantly enriched in light rare earth elements. They are granoblastic and mainly composed of quartz and plagioclase grains in a fine-grained recrystallised matrix of chlorite, sericite, epidote, quartz and plagioclase. Accessory minerals include apatite, sphene and sulphides. Two samples to the east returned intrusion ages of 2710 ±6 Ma and 2703 ±8 Ma and inherited zircons at 2755 Ma and 2810 Ma (U-Pb, zircon).
iv). Several oxide and silicate facies iron formation lenses, interstratified with, and at the top of the amphibolitised basalts. These are <150 m thick, with strike lengths of up to 8 km. The oxide facies are characterised by massive, black to bluish grey magnetite bands that are a metre or more in thickness, alternating with granoblastic chert bands. The silicate facies iron formations comprise magnetite bands and laminae alternating with hornblende-garnet-biotite-chlorite rich magnetic, and magnetite paragneiss layers.
v). Amphibolite derived from komatiitic basalt, which occurs as layers that are tens to hundreds of metres thick, is interstratified in the basaltic sequence, and is apparently spatially associated with a felsic volcanic unit. These amphibolites are dark green, fine to medium grained and foliated, with >90% actinolite and accessory serpentine.
As mentioned previously, where the Lac des Montagnes Belt structurally abuts the Nemiscau Subterrane to the SW, a unit of amphibolitised basalt and andesitic basalt, and a unit of felsic volcaniclastic rock, which are locally intruded by granite and granitic pegmatite dykes, is an apparent continuation of the Lac des Montagnes Group into the latter subprovince. However, as the Lac des Montagnes Belt is now taken to be part of the La Grande Subprovince, this suite, previously considered to belong to the Lac des Montagnes Group, is now known as the Peat Formation.
• The overlying Neoarchaen Voirdye Formation, which extends discontinuously over an ENE-WSW to east-west and strike length of ~280 km and is exposed over a width that varies from 2 to 11 km. It is a metasedimentary unit mainly composed of paragneiss derived from wacke and arenite, stratigraphically divided into the following units that are variably developed:
i). Conglomerate, that is mainly matrix supported and polymictic, containing subrounded, stretched cobble to boulder sized mafic and felsic clasts, set in a quartzo-feldspathic to micaceous matrix. The composition of the matrix is dependent upon the intensity of deformation. These conglomerates are only observed very locally, and tend to be located near deformation zones.
ii). Biotite-hornblende-garnet ±sillimanite ±cordierite paragneiss after wacke, and locally arenite, protoliths. This is the most important unit of the formation. The wacke derived facies are grey to brownish grey, mostly fine grained, but locally medium grained, and generally homogeneous and foliated. Sedimentary bedding that varies from tens of cm in thickness to millimetre laminae are locally observed. This paragneiss contains 20 to 35% x 0.5 to 5 mm biotite and trace to 5% x 1 to 3 mm garnet.
Centimetre to tens of cm thick bands of paragneiss derived from arenite are interstratified with those after wackes. They are distinguished by their lighter pale-medium grey colour, lower content of 5 to 15% biotite, and only local traces of garnet.
Three sub-units of this paragneiss have also been differentiated:
- Biotite-garnet ±cordierite ±sillimanite Nodular Paragneiss, distinguished by the presence of aluminosilicate porphyroblasts, dominantly sillimanite and cordierite, which vary in diameter from 2 to 20 mm and account for 25 to 40% of the rock.
- Arkosic and subarkosic paragneiss - distinguished by its greater plagioclase and K feldspar content. It is medium-light whitish grey to brownish grey or medium-light beige grey, and fine to medium grained, with 1 to 15% x 0.5 to 2 mm biotite, and trace to 1% x1 mm garnet.
- Metatexite, derived from partial melting of the paragneiss and migmatised paragneiss - these metatexites contains 10 to 40% remobilised granitic fractions and 60 to 90% restite. The restite is usually fine to medium grained and foliated, and is grey to medium-light brownish grey with 20 to 30% x 1 to 5 mm biotite. It sometimes contains garnet and cordierite-sillimanite porphyroblasts. The remobilised granitic fraction is medium to coarse grained, medium-light whitish grey to light whitish beige, heterogeneous and hetero-granular. It is predominantly injected subparallel to the main foliation, producing a stromatic texture. The migmatites are primarily distinguished from the metatexite by their lower 5 to 10% remobilised fraction abundance.
iii). Quartzite - lenses that are tens to hundreds of metres in thickness, with strike lengths of 1 to 5 km. These are light beige grey to whitish grey, and medium grained, laminated and foliated, usually with a saccharoidal texture. The most common accessory mineral is 1 to 10% garnet, followed by 1 to 5% muscovite or biotite.
iv). Oxide and silicate facies iron formation, that are tens of centimetres to a metre in thickness, have been locally encountered in outcrop. These iron formations have silicate-oxide facies mineralogy. More locally, typical oxide facies and, very locally, silicate and sulphide facies horizons are observed.
v). Garnet-cordierite ±sillimanite ±anthophyllite metsomatic rock, outcrops of which have been locally mapped. These do not apparently represent large masses. No intrusive contact or transition to unaltered host have been observed and they are interpreted to likely be the result of hydrothermal alteration overprinted by regional metamorphism. They are composed of anthophyllite, cordierite, garnet, sillimanite, quartz, magnetite and locally chlorite. One variation is characterised by the presence of lenses of arenite hosted garnetite that are cm to tens of centimetres in thickness.
Metatexites, as described in the second unit of the Voirdye Formation above, are generally more prevalent in the SW end of the Lac des Montagnes Belt, whereas they are almost absent in section around the Whabouchi Mine and further to the east of the belt. The Voirdye Formation is generally distinguished by the ubiquity of primary sedimentary structures, the abundance of sedimentary rocks with metamorphic mineral assemblages (e.g. biotite-sillimanite-cordierite) and the scarcity of migmatised sedimentary rocks (<1% of the unit).
In contrast, from ~40 km to the SW of the Nemaska Lithium Project area, to the SW in the Nemiscau Subprovince, the pobable equivalent of the Voirdye Formation is more strongly metamorphosed and migmatised/anatectic, with ~95% migmatitic rocks, whilst metamorphic mineral assemblages such as sillimanite and cordierite, as found in the main Voirdye Formation, are generally absent. In the southwestern extremities of the Lac des Montagnes Belt and in the Nemiscau Subprovince, his migmatitic/anatectic sequence is described as the:
• Rupert Complex which includes variably migmatised meta-sedimentary rocks that stratigraphically overlie the Lac des Montagnes Group. These are found in the southeastern end of the Lac des Montagnes Belt and over a larger area in the structurally juxtaposed main Nemiscau subprovince. The complex has been divided into five lithofacies:
i). Biotite-hornblende-garnet ±sillimanite ±cordierite paragneiss containing <10% remobilised fractions.
ii). Migmatised paragneiss containing 10 to 20% remobilised fractions. These are not widespread, with the largest develoments interstratified with the first facies, but are also found in the middle of diatexites of the fourth facies.
iii). Metatexite after paragneiss containing 20 to 50% remobilised fractions. It is well exposed in the south of the region, at the contact of, or within the middle of the fourth lithofacies.
iv). Comprises migmatites after paragneiss containing 50 to 90% remobilised fractions and interpreted as diatexites/anatexites.
• Lac des Montagnes Ultramafic Intrusion which extends in a ENE direction over 5 km strike and width of 100 to 240 m, ~10 km SW of the Whabouchi Mine, and <1 km SSE of the Riviére Rupert Shear Zone (not shown on the image above). It intrudes both amphibolitised basalt, biotite-hornblende-garnet ±sillimanite ±cordierite paragneiss and quartzite (units i)., ii). and iii). of the Voirdye Formation as described above). It is an ultramafic intrusion with well-preserved rhythmic magmatic layering and metre to tens of metres-thick zones of banded chromitite. It has been divided into three lithological units, from the base to the top i.e., from north to south:
i). peridotite, which is black or dark green to locally light green to coffee brown. accounts for over half of the area of the intrusion and contains three chromitite zones with lateral extensions of from 292 to 500 m. The principal characteristic of the chromitite zone is the ubiquitous, NE-SW oriented and SE-dipping rhythmic magmatic layering. This layering is highlighted by sorted, mm to cm thick alternating chromite-rich and peridotite layers. The peridotite is serpentinised, and metamorphosed into talc, but has a well-preserved cumulate texture. The contact between peridotite and chromitite layers is sharp at the base, and wavy and gradational towards the top.
ii). pyroxenite, that is greenish grey and medium to coarse grained, and
iii). gabbro which is of mesocratic to melanocratic.
The preceding sequence, up to and including the Voirdye Formation are intruded by small lenticular masses of the:
• Caumont Mafic-Ultramafic Suite, which comprises mafic and ultramafic sills of peridotite, pyroxenite and gabbro, of limited extent. Some sills, in places, carry thin horizons of peridotite containing acicular rods of serpentine, interpreted as olivine spinifex relics in a komatiitic lava. The normative composition of peridotite is harzburgite, whilst that of pyroxenite is olivine websterite, and that of mafic rocks is norite and gabbronorite. Ultramafic rocks are of komatiitic to tholeiitic affinity, while mafic rocks are tholeiitic. This suite is largely confined to the Lac des Montagnes Belt.
The succession above is intruded, in turn, by the:
• Senay Suite, which is a white to beige-pink, biotite ±garnet ±muscovite ±tourmaline granitic pegmatite, usually associated with migmatitic rocks of the Voirdye Formation/Rupert Group. It is interpreted to represent a foliated S-type granite, and has been dated at 2672 ±2 Ma (Davis et al., 1995). It commonly contains paragneiss enclaves which are metres to tens of metres across that are usually boudinaged, and locally comprise partially digested restites. It typically contains up to 10% biotite, up to 5% muscovite, 1 to 5% garnet and magnetite grains that are either disseminated or in centimetric clusters. The suite is interpreted to be the most evolved rocks from partial melting of metasedimentary rocks of the Voirdye Formation/Rupert Group. Geochemically, they are peraluminous. Large masses of these pegmatites are found in the Lac des Montagnes Belt, but also in the Champion Complex of the La Grande Subprovince, whilst very similar age and lithologies within the Nemiscau Subprovince to the SW are known as the Meziéres Suite.
• Spoduméne Suite, dyke swarms of which that are of sufficient grade and thickness form lithium ore deposits. This suite groups intrusions of white spodumene-muscovite-garnet-tourmaline ±beryl ±apatite ±lepidolite ±petalite pegmatite. In the Nemaska district, these pegmatites were emplaced into shear zones that cut amphibolitised basalts [Unit i).] of the Lac des Montagnes Group, proximal to the sheared contact zone between the main La Grande Subprovince and the Lac des Montagnes Belt. The most significant of these intrusions are the Whabouchi and Graab pegmatites, located NE of Montagnes Lake and east of Andalousite Lake, respectively. Graab is ~30 km to the ENE of Whabouchi. The spodumene pegmatite is whitish, locally pinkish and massive to foliated. The massive variety locally exhibits magmatic layering, characterised by alternating, centimetric, medium-grained layers and coarse-grained or pegmatitic layers. These layered intervals are ~1 to 2 m thick. A syntectonic to late-tectonic emplacement is implied by the generally deformed and sheared margins of these intrusions and boudinaging of their apophyses.
Typical spodumene pegmatite is composed of 30 to 40% K feldspar, 20% plagioclase (albite), 20% quartz, 15% muscovite and 5 to 30% spodumene. Accessory minerals are spessartine garnet, tourmaline, beryl, apatite, lepidolite, petalite and biotite, the latter appearing close to contacts with the host rocks. In detail, K feldspar is replaced by albite.
The pegmatite is mostly homogenous, with the greatest variability being with respect to the minerals albite, K feldspar and spodumene. The Li2O concentration varies between 0.03 and 4.46 wt.%, for an average of 1.53 wt.% and an estimated variability of 53%. Modal mineralogical data shows an inverse correlation between spodumene and the feldspars (albite + K feldspar), which could also be observed when comparing the Li2O content with the sum of Na2O + K2O (Morissette et al., 2022).
Spodumene crystals are usually apple green to locally whitish, euhedral, and range in size from 0.5 to 55 cm in length. They have no apparent preferred orientation within the pegmatitic mass, although megacrystals are generally oriented parallel to layering. Where layered, those that are coarse-grained are the richest with up to 40% spodumene. Some 2 to 15% of the spodumene is disseminated in the pegmatite, whilst locally, 40% is semi-massive or forms monomineralic veins.
At the Whabouchi Mine, white spodumene-bearing granitic pegmatite (containing 25 to 30% spodumene) occurs as a swarm of interconnected dykes intruded into deformed aplitic phase zones. The aplitic phase is white, saccharoidal and composed of 60% albite, 20% light grey quartz, 20% muscovite and 1% garnet. At Graab, tourmaline rods are intergrown in spodumene cleavage planes.
Geochemically, the granitic pegmatite of the Spoduméne Suite is S-type, peraluminous and classified as a member of the LCT family (Li-Cs-Ta > Nb), enriched in Rb, Sn, Be, B, P and F (Cerny and Ercit, 2005). The parent magma is interpreted to have been generated by anatexis of crustal sedimentary or igneous rocks at shallow to medium crustal depths (Beland, 2011; Bynoe, 2014).
Zircons from the Whabouchi deposit's spodumene pegmatite, returned a crystallisation age of 2577 ±3 Ma (Beland, 2011), demonstrating that this unit is the latest felsic intrusive phase of the La Grande Subprovince.
Spodumene contains 8% Li2O when pure, but usually also contains minor amounts of niobium and tantalum. Typically, the Whabouchi pegmatite sampled from drill core averages 1.42% Li2O with values up to 5.19% Li2O. Mineralogical studies have identified minor amount of other Li-bearing minerals at Whabouchi, including petalite, muscovite, ferrisicklerite, cookeite and holmquistite.
Poste Albanel Shear Zone
The Poste Albanel, Shear Zone is a major ENE to NE trending, SE dipping, ~180 km long, regional reverse dextral structure. It defines the southern margin of the Lac des Montagnes Belt which is interpreted to mark the southern margin of the La Grande Subprovince, following the contact with the Opatica Subprovince. It is not well exposed although its forms a corridor of heavily deformed gneissic rocks with granitic injections and boudinaged quartz veins. The Quebec Ministére des Ressources naturelles et des For&eacirc;ts SIGÉOM GIS interactive map (viewed December, 2024) shows this structural zone continuing to the east, then ESE and SE for a further 190 km, still separating the Lac des Montagnes Belt lithologies and the Opatica Subprovince, as shown on the regional image above.
Nemiscau Subprovince
The Lac des Montagnes Belt is juxtaposed across across transform faults and south-vergent thrusts, over the Nemiscau Subprovince. The two elements contain many similar lithological units, until recently regarded as representing the same stratigraphic succession, which has undergone a different metamorphic history, but are in different subprovinces. The key elements are the:
• Mesoarchaen basement De Wettigo Complex - composed of plutono-gneissic rocks of generally tonalitic to granodioritic composition with lesser local dioritic or granitic phases. These occur as a series of aligned domes subdivided into the following: i). granitic tonalitic gneiss; ii). metatexite derived from tonalitic to dioritic rocks; iii). diatexite derived from tonalitic to dioritic protoliths; iv). pyroxene-hornblende granodiorite; v). biotite-hornblende granodiorite; and vi). pyroxene-hornblende tonalite and granodiorite.
• Neoarchaean Peat Formation, as described above at the end of the Lac des Montagnes Group segment in the Lac des Montagnes Belt section.
• Neoarchaean Mezieres Suite, which is temporally and lithologically similar to the Senay Suite of the the Lac des Montagnes Belt section, as described above.
• Neoarchaean Masayuqui Suite, which consists of two units, i). pink biotite ±magnetite granite; and ii). pink granitic pegmatite. These represent the latest intrusive phase of the Nemisau Subprovince. They intrude into the migmatites of the Rupert Complex, and occur along shear zones.
Opatica Subprovince
The northeastern section of the Opatica Subprovince, to the SE of the Poste Albanel Shear Zone and the Lac des Montagnes Belt, is dominantly composed of the Mesoarchaean plutono-gneissic Théodat Complex, which is overlain by rocks correlated with the Voirdye Formation of the Lac des Montagnes Belt, and intruded by the more restricted Neoarchaean La Sicotiére Suite, the extensive Canards Suite granitoids and the Kaupanaukau Suite, which has been dated at 2598.6 ±7.2 Ma (Pedreira Perez et al., 2023).
• The Théodat Complex is one of the largest plutono-gneissic masses in the Opatica Subprovince, extending for 220 km east-west and 50 to 85 km north-south, limited to the north by the Nemiscau, La Grande and Opinaca subprovinces, and by the Lac des Montagnes Belt. It is understood to be the eastern extension of the tonalitic Mesoarchaean Rodayer Pluton that is interpreted to represent basement to the Neoarchaean volcano-sedimentary sequences. A tonalitic gneiss sample from the Théodat Complex has returned a crystallization age of 2833.5 ±3 Ma (David, 2020), comparable to that of the Lac Rodayer Pluton that was emplaced between 2830 and 2820 Ma (Davis et al., 1994, 1995). As such it is older than the Lac des Montagnes Group of the Lac des Montagnes Belt, but overlaps the age of the Hutte Complex that is basement to that group within the Lac des Montagnes Belt.
The Théodat Complex comprises the following:
i). Grey to beige tonalitic gneiss that is homogeneous to heterogeneous, granoblastic, locally schistose and sheared. It encloses phases that include dioritic gneiss and diatexite/migmatite that is derived from tonalitic to dioritic protoliths.
ii). Foliated, fine to medium grained, grey-beige to whitish pink biotite ±hornblende granodiorite containing tonalite enclaves.
iii). Light grey to pinkish grey porphyritic hornblende-biotite granodiorite that is massive to foliated, homogeneous and medium to coarse grained with disseminated K feldspar phenocrysts. It includes two separate phases, a porphyritic quartz monzodiorite, quartz monzonite and locally granodiorite, and foliated diorite and quartz diorite.
iv). Pinkish beige to pinkish grey biotite ±magnetite granite that is medium to coarse grained, locally pegmatitic and massive, with enclaves of foliated to gneissic tonalitic rocks.
v). Light pink, granitic pegmatite that is usually massive, with a widespread graphic texture, ranging from pegmatitic or coarse grained to locally medium grained. It contains enclaves of all the other units of the Théodat Complex.
• The Neoarchaean Voirdye Formation, which unconformably overlies the Mesoarchaean Théodat Complex, and comprises both i). biotite ±garnet ±sillimanite ±cordierite paragneiss derived from wacke and locally arenite, and ii). more intense metatexite derived from similar paragneiss and migmatised paragneiss. See also the Rupert Complex of the Nemiscau Subprovince and Voirdye Formation of the Lac des Montagnes Belt, as described previously.
• The Neoarchaean La Sicotiére Suite is relatively well developed on the western margin of the subprovince, where it cuts the Théodat Complex, but is also present across the Poste Albanel Shear Zone in the southwestern Lac des Montagnes Belt, where it intrudes diatexites of the main mass of the Voirdye Formation/Rupert Complex, but is, in turn, crosscut by masses of the Kaupanaukau Suite. Geophysical and geological data reveal that it extends NW-SE to NNW-SSE,over an area of at least 21 x 8 km. It is composed of two units:
i). A porphyritic quartz monzodiorite and quartz monzonite unit, with local porphyritic granodiorite. All of these rocks are medium to coarse-grained, weakly to strongly foliated, homogeneous and very strongly magnetic. Geochemically, they are rich in potassium (1.5 to 4.3%), metaluminous and typically devoid of europium anomalies; and
ii). A foliated porphyritic granodiorite unit that is medium to coarse-grained, homogeneous, and slightly to moderately magnetic. It is moderately enriched with potassium (1.7 to 3.1%), metaluminous, and also is typically devoid of europium anomalies. Isotopic dating of a porphyritic granodiorite of this unit returned an age of 2693 Ma, interpreted as the age of emplacement (David, 2020).
• The Neoarchaean Canards Suite occurs as a series of mainly biotite granite intrusions that are pink, medium to coarse-grained, locally pegmatitic and typically foliated to locally gneissic. They include up to 10% metre scale enclaves of brownish paragneiss and geochemically are peraluminous, of calc-alkaline/calcic affinity, moderately to strongly enriched in potassium, and characterised by negative europium anomalies. They intrude the rocks of the Théodat Complex and occur as a long, discontinuous chain of intrusions that are hundreds of metres to several km across, the largest of which is 25 x 7 km. As stated previously, they overlap the Opatica, Nemiscou and La Grande subprovinces, and the Lac des Montagnes Belt and are the youngest Archaean intrusives of the area.
Mafic Dykes
All of the above are cut by a series of dyke swarms, namely: i). the NW-SE oriented, 2515 ±3 Ma Mistassini olivine gabbronorite; ii). the NE-SW oriented, 2221 ±4 Ma and 2216 +8/-4 Ma Senneterre gabbronorite; and iii).the east-west oriented, 1141 ± 2 Ma Abitibi olivine gabbro.
Deposit Geology and Mineralisation
See the description of the Spoduméne Suite above.
The Whabouchi lithium deposit occurs as a cluster of bifurcating, sub-parallel crosscutting pegamatite dykes of the Spodumene Suite, defining an elongate zone that extends over a length of 1.3 km x 130 m in width. The swarm persists to a depth of >300 m below surface, and is open at both depth and to the east. The main dyke is in the NW, and is between 40 and 80 m thick. Two groups of secondary dykes, located to the SW and NE, are each about 10 m thick. The dyke swarm is oriented at 60° and dips at 70 to 80°, averaging 75°SE. The western sector of the swarm, which is characterised by thick subvertical dykes which thin and bifurcate to the east, accounts for the bulk of the measured and indicated resources. To the south, the swarm has been folded and tend to dip towards the south.
At Whabouchi, the Spodumene Suite dykes are composed of white granitic, rare element, zoned pegmatite containing quartz, albite, spodumene, microcline and large sheets muscovite with lesser garnet and apatite. Locally bluish apatite is more evident, with <1% fine yellowish beryl crystals. The pegmatite is elongated parallel to the foliation of the amphibolitised mafic volcanic country rocks of the Lac des Montagnes Group. Petrographic analysis of a pegmatite sample yielded: 52% quartz, 26% plagioclase (albite), 16% spodumene, 2% muscovite, minor microcline and accessory apatite and garnet. Under the microscope, the pegmatite consists of 20 vol.% spodumene, 5 to 50 vol.% smoky quartz, 5 to 80 vol.% feldspar and 5 to 95 vol.% albite. Locally, coarse-grained crystals of petalite and beryl are evident, as well as generally fine-grained garnet (Quebec Ministére des Ressources naturelles et des Forêts).
Mineralisation comprises pale green spodumene crystals disseminated within the pegmatite, with local coarse-grained crystals of petalite. Lithium is found almost exclusively in spodumene. The pegmatite dykes exhibit zonation with a border, a wall, an intermediate and a central zone. Mineralization is concentrated in the intermediate zone of coarser grain size. However, as the pegmatite is heterogeneous and zoned, the proportions of spodumene vary from 0 to 50% of the rock.
The smaller, historically mined Graab mineralisation, some 30 km to the ENE is hosted by a single main pegmatite dyke that extends over a strike length of ~2230 m in a NE-SW direction. It too is hosted within meta-basalt of the Lac des Montagnes Group. The pegmatite consists of quartz, feldspar, muscovite, garnet, apatite, tourmaline and spodumene. Mineralization comprises 2 to 3%, locally up to 15%, spodumene crystals that are usually pale green and centimetre-sized, reaching as much as 20 cm in length. White idiomorphic beryl crystals have also been noted.
Numerous other lithium occurrences are known between the Whabouchi and Graab mineralised pegmatites, and for at least 5 km to the SW of the former. Elsewhere, regionally, lithium occurrences are found both concentrated along major structures, and distal to such structures both, in basement and in Eastmain Group country rock.
Resources and Reserves
The Ore Reserves and Mineral Resources of the Whabouchi Deposit, as of 31 December 2022 (SEC Technical Report Summary for the Pre-Feasibility Study
on the Whabouchi Mine, Nemaska, Quebec, November, 2023. Prepared by BBA Inc., DRA Americas Inc., SGS Geological Services and WSP Canada Inc. for Nemasca Lithium), were:
Ore Reserves
Proved Reserve - 10.5 Mt @ 1.40% Li2O;
Probable Reserve - 27.7 Mt @ 1.28% Li2O;
Proved + Probable Reserve - 38.2 Mt @ 1.31% Li2O for 0.50 Mt of contained Li2O.
Mineral Resources
Indicated Resource - 7.8 Mt @ 1.61% Li2O for 0.16 Mt of contained Li2O;
Inferred Resource - 8.3 Mt @ 1.31% Li2O for 0.108 Mt of contained Li2O;
NOTE: Resources are exclusive of Reserves. A metallurgical recovery of 85% was assumed. The Ore Reserves are inclusive of mining dilution and ore loss.
The Technical Report cited above suggests mining will initially be by open pit, but by Year 25, is expected to be operating from underground by transverse long-hole mining method. To accommodate this the Proved + Probable Ore Reserves are split as follows:
Open Pit Ore Reserves - 26.5 Mt @ 1.32% Li2O;
Underground Ore Reserves - 11.7 Mt @ 1.29% Li2O.
As of 26 June, 2019, Open Pit and Undergound Mineral Resources were split as follows, based on cut-off grades of 0.3 and 0.6% Li2O respectively were (SGS Geostat, 2019):
Open Pit Mineral Resources
Measured Mineral Resources - 17.734 Mt @ 1.60% Li2O,
Indicated Mineral Resources - 20.532 Mt @ 1.33% Li2O,
Inferred Mineral Resources - 11.745 Mt @ 1.27% Li2O,
Underground Mineral Resources
Indicated Mineral Resources - 0.274 Mt @ 1.13% Li2O,
Inferred Mineral Resources - 5.413 Mt @ 1.32% Li2O.
The information in this summary has been predominantly drawn from the Quebec Ministére des Ressources naturelles et des Forêts SIGÉOM GIS interactive map (viewed December, 2024) and files from the main website linked to that map, as well as the SEC Technical Report Summary for the Pre-Feasibility Study on the Whabouchi Mine, Nemaska, Quebec, November, 2023. Prepared by BBA Inc., DRA Americas Inc., SGS Geological Services and WSP Canada Inc. for Nemasca Lithium.
The most recent source geological information used to prepare this decription was dated: 2024.
This description is a summary from published sources, the chief of which are listed below.
© Copyright Porter GeoConsultancy Pty Ltd. Unauthorised copying, reproduction, storage or dissemination prohibited.
Whabouchi Mine
|
|
|
|
Morissette, C.L., Cecchi, E. and Blais, J.-F., 2022 - Mineralogical Variability of the Whabouchi Pegmatite and its Effect on the Li Concentrations: in The Canadian Mineralogist v.60, pp. 759-774.
|
Moukhsil, A., Legault, M., Boily, M., Doyon, J., Sawyer, E. and Davis, D.W., 2007 - Geological and metallogenic synthesis of the Middle and Lower Eastmain greenstone belt (Baie-James): in Bureau de l exploration geologique du Quebec Report ET 2007-01 59p.
|
Perez, R.P., Tremblay, A. and Steveneson, R.K., 2024 - Archean crustal growth and reworking in the Superior Province, Canada: Insights from whole-rock geochemistry and Nd isotopic data of the La Grande, Nemiscau and Opatica subprovinces: in Gondwana Research v.135, pp. 151-179.
|
|
Porter GeoConsultancy Pty Ltd (PorterGeo) provides access to this database at no charge. It is largely based on scientific papers and reports in the public domain, and was current when the sources consulted were published. While PorterGeo endeavour to ensure the information was accurate at the time of compilation and subsequent updating, PorterGeo, its employees and servants: i). do not warrant, or make any representation regarding the use, or results of the use of the information contained herein as to its correctness, accuracy, currency, or otherwise; and ii). expressly disclaim all liability or responsibility to any person using the information or conclusions contained herein.
|
Top | Search Again | PGC Home | Terms & Conditions
|
|
