Projects Overview Newfoundland & Labrador British Columbia
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Detailed GeologyFreeport is now assessing the Q property's molybdenum potential, with work to confirm historical fluorite reserves also underway.
Widespread host rock potassic alteration suggests intense hydrothermal activity as often seen in porphyry deposits. The most obvious is the large-scale salmon pink potassic feldspar alteration in the fluorite-mineralized area. A recently completed study suggests that mineralization may be related to a well-differentiated Cretaceous granitic intrusion at depth.
Molybdenite has been observed in both adits -- 300 m (984') apart -- and mentioned in a number of drill hole logs. Extensive assays of samples from Adit 2 show many elevated Mo values greater than 100 ppm, with values between 500 and 1100 not uncommon in the northeast section. This area --the "East Drift" -- is near the contact with the sedimentary rock, and characterized by increased faulting and structural complexity.
Similarities to Porphyry DepositsPorphyry deposits are typically low grade, high tonnage, and hosted by granitic intrusive rocks. Mineralization is found within the porphyritic granitic intrusion, within veinlets and fracture stockwork cross-cutting the intrusion, and also in the regional host rock.
The nearest porphyry deposits to the Q include:
Property GeologyFluorite, molybdenite, silver and celestite mineralization at the Q is hosted by Quesnel Lake orthogneiss of Late Devonian to Early Mississippian age near the contact with Late Proterozoic Snowshoe Group metasedimentary rocks. Overburden covers much of the property, with generally somewhat limited outcrop. Barrett Creek canyon crosses the mineralized zone from north-east to south-west, clearly exposing the intrusive contact where granitic gneiss crosscuts metasediments, with large blocks of metasediments included within the orthogneiss near its margins. Dykes and small bodies of aplitic rocks as well as a few narrow lamprophyre and feldspar porphyry dykes have also been observed.
Distribution of fluorspar (calcium fluoride) as well as celestite (strontium sulphate) is mainly controlled by fracturing of more brittle host rocks, and percolation by hydrothermal fluids. Review of high resolution air photo imagery confirms a concentration of linear fracture patterns at the northeast end of Adit 2, near the contact between granitic orthogneisses and metasedimentary rocks. This zone coincides with an area of significant fluorspar mineralization as well as elevated MoS2 in Adit 2 and nearby drill holes samples analyzed by Freeport.
Work at the property includes drilling of 126 surface holes (19,687 m, or 64,590'), and 9 underground holes (1,525 m, or 5003'). Two adits (No. 1: 292 m or 958'; and No. 2: 373 m or 1224') were also driven in the 1980's. This work defined eight fluorite lenses or zones.
MineralizationRecent work at the Q includes completion of the first mineralogical and petrographic review, entitled Eaglet Property Revisited: Fluorite-Molybdenite Porphyry-like Hydrothermal System", (Hora et al., BCGS 2008). This study provides detailed information on different types of mineralization and relationships of individual minerals of economic interest. Pyrochlore (a niobium mineral), and a bastnaesite-related mineral (Ce, Y, CO3 F carbonate) were both newly discovered. Five randomly collected samples assayed for Nb resulted in values up to 857 ppm, with pyrochlore present in amounts up to several volume percent in some, found in association with microcline, zircon, and pyrite. Zinnwaldite, a potassium lithium mica, was also identified.
A study in 2009 by the same author, entitled Niobium-Thorium-Strontium-REE Mineralogy and Preliminary Sulfur Isotope Geochemistry of the Eaglet Property East-Central British Columbia (NTS 093A/10W), provides a more detailed evaluation of the Nb-Th-Sr-REE mineralogy, and based on sulfur isotope suggests at least two different sources of mineralization at the property -- namely that the sulfate minerals (celestite) and sulfide minerals (pyrite and molybdenite) were formed independently at different stages of the ore-forming process. This study is in progress.
FluoriteFluorite mineralization seems associated with late, unfoliated white and pink aplite dikes intruding the Quesnel Lake orthogneiss and the schists of the Snowshoe Group. It occurs as disseminated grains, fracture fillings, stockwork and irregular veins and replacement bodies within the gneiss and aplitic rock. Dark purple fluorite -- enriched in thorium and light REE relative to the later green and colourless varieties -- is possibly associated with molybdenite, while the later are associated with carbonates and celestite (Hora et al., 2008). Small quantities of galena, sphalerite, and pyrite are also common visible accessories with purple fluorite.
Described as 8 'stacked' sheet-like zones, the fluorite lenses range in thickness from 5 to 30 meters (98'), with an average of eight metres. Grade ranges from a few percent to 43% CaF2, generally increasing with depth. There are 4 'main zones', typically no more than 10-15 m (33-49') apart. The best zone is at the contact between the Snowshoe schist and the orthogneiss, forming a 100 m (328') east-west and 150 m (492') north-south sheet. It is intercepted by Adit 2 as well as drill holes, at approximately 100 to 150 m (328 to 492') depth from surface, with ~10% CaF2. Smaller fluorite lenses occur above and below the main zone.
Historical Fluorite Reserves
In 1984, Eaglet Mines calculated reserves at 24 million tonnes averaging 11.5% calcium fluoride (CaF2), with silver, molybdenum, and lead by-products, as follows:
1. Probable "drill indicated" economic mineralization: 11,000,000 tonnes
2. Inferred economic mineralization: 13,000,000 tonnes
Total: 24,000,000 tonnes (26,450,000 tons)
Including 1,800,000 tonnes of 15% CaF2 ore (Minfile 093A 046)
Reserves included at least 2,000,000 tonnes (2,205,000 tons) of higher grade fluorspar ore in a 6 metre (20') thick zone intersected by Adit 2. Preliminary metallurgical testing by Eaglet Mines produced both acid and metallurgical-grade concentrates in a cold water flotation circuit using an inexpensive, nontoxic, and readily biodegradable reagent scheme.
Please note that historical estimates pre-date and are not compliant with NI 43-101. Freeport has not verified the historical estimates and they should not be relied upon. However, Freeport believes that they provide a conceptual indication of mineral potential and are relevant to continuing exploration.
The first comprehensive analytical results confirming widespread presence of molybdenum (Mo) in Adit No. 2 were released by Freeport. Approximately 25% of over 500 pulp samples have anomalous molybdenum, from 100 ppm to a maximum of 1143 ppm (0.19% MoS2).
A digital map of Adit 2 including geology, structure, Mo and fluorite rich zones has recently been prepared, as part of a 3D modelling study to compare distribution of molybdenite, fluorspar and also alkalic alteration zones similar to known porphyry deposit models.
UBC Mining Research Ltd (BCMR - Dr. Bern Klein) recently completed a metallurgical test study for Freeport, to determine if it were possible to produce a commercial-grade molybdenum concentrate and design a process flow sheet. A 20 kg grab sample with a high grade of 0.16% Mo resulted in an initial concentrate with 31.0% Mo (51.7% MoS2), with associated rhenium (22.1 g/tonne, 0.64 oz/ton). These results are very encouraging and further work has been recommended.
SilverSilver is commonly present in amounts up to 1 oz per ton (34.3 g/tonne), with a maximum reported value of 15 oz (514 g/tonne). In Adit 2, it occurs in galena in zones up to 30 cm (12") wide within the area of higher grade fluorite. Zones up to 3 m (10') wide have assayed 0.5 oz (17 g/tonne) silver per ton, and 1% lead (McDougall & Ball, 1994).
CelestiteCelestite, or strontium sulfate (SrSO4), is mostly produced from sedimentary evaporate deposits. Elsewhere, it is also found in veins sometimes associated with galena, sphalerite and other sulfides. Carbonatites, intrusive carbonate rocks, are frequently celestite-enriched.
High values of strontium in all samples analyzed by Freeport (many over 10,000 ppm) indicate widespread presence of celestite disseminated throughout the deposit.
Alteration MineralsAlteration minerals observed by past and more recent work include Na-feldspar, K-feldspar, biotite, sericite, muscovite, gypsum, pyroxene, chlorite, and kaolinite. Newly identified alteration products include siderite, disseminated hematite, calcite, dickite, nakrite, kaolinite, and fluorapophyllite.
Conclusion and RecommendationsFreeport is now reassessing the Q as a potential molybdenum deposit and is seeking involvement of a major company. The following is recommended: