The Peak occurrence is located at an elevation of approximately 1950 metres on a northwest-southeast–trending ridge, approximately 2.6 kilometres south of Shedin Peak.
Regionally, the area is underlain by clastic sedimentary rocks of the Middle Jurassic to Upper Cretaceous Bowser Lake Group, which have been intruded by granodiorite of the Upper Cretaceous Bulkley Plutonic Suite. Hornfels and calc-silicate skarn is developed in the contact area of the intrusion.
Detailed mapping in the Fog-Peak target area in 2014 identified two phases of monzonite and three phases of dikes. The oldest monzonite (MZ1) is a moderately foliated medium- to coarse-grained intrusion with up to 5 per cent megacrystic square, zoned feldspar phenocrysts. There is a dark-grey chilled contact with the neighbouring sediments and foliation is parallel to that in the sediments, which is steeply west dipping in the two eastern cirques of the Fog ridge. The MZ1 unit has potassium feldspar stockwork, barren grey quartz veins, aplite dikes and many crosscutting vein types that appear to increase in intensity towards the east at and/or below the contact with the sediments. The younger monzonite (MZ2) outcrops extensively in the area and is a buff to pink, medium- to coarse-grained megacrystic intrusion with up to 10 per cent pink, zoned potassium feldspar phenocrysts. The contact with the MZ1 phase is not exposed and the two units may be gradational into each other.
Three generations of dikes were identified in the area; the highest concentration of dikes appears to correlate with the location of the MZ1 phase of monzonite. D1 is quartz-feldspar-biotite porphyry with 5 per cent small white (sericitized) feldspar phenocrysts; 3 per cent glassy quartz eyes to 2 millimetres and 3 per cent fine-grained red, shreddy biotite and disseminated pyrite. The matrix is siliceous and distinctly white. Portions of the dike have potassium feldspar network veinlets similar to MZ1 and it appears that all vein types cut this dike. The exposure of the dike strikes north-south and dips steeply west subparallel to the foliation in the sediments and MZ1, but has apophyses leading northeast from the main dike. There is no apparent foliation in the D1 dike. D2 is a white feldspar porphyritic dike with smaller quartz and biotite phenocrysts and a grey matrix. These dikes typically trend east-west, dip steeply to the south and cut the D1 dike. In part of the area these dikes form another east- west corridor and cut a quartz-feldspar porphyry sill that could be part of the D1 event. The D3 event is fine-grained mafic dikes found in the central and northeast part of the Fog area. The dikes are dark-green and chloritic with 1-centimetre hornblende or pyroxene phenocrysts. The dikes cut pegmatite and quartz veins and one D3 dike is seen to be displaced by a west-northwest–trending shear.
Sediments in the area are comprised of argillite, greywacke and arenite. Disseminated pyrite occurs throughout most of the stratigraphy and red-coloured shreddy biotite is evident in the arenite. Calcareous portions of the stratigraphy are seen in the central cirque near the D1 ‘white’ dike, where they are altered to skarn including garnet, epidote and diopside. Fragments and irregular veins of garnet with lesser epidote are incorporated in the D1 dike where it cuts through the skarn. Iron oxide alteration that is related to pyrite as disseminations or in veins is identified in the area and occurs in both the monzonite and sediments.
Locally, a complex quartz vein system in a felsite dike contains copper and molybdenum mineralization over a width of 3.9 metres and a length of 130 metres. Pyrite, chalcopyrite and molybdenite are also present in the hornfelsed area adjacent to the stock. A full description of vein types and mineralization in the area can be found in the Fog (MINFILE 093M 125) occurrence.
Work History
In 1969, Chataway Exploration Co. Ltd. explored the area as the Peak claims. Also at this time, the 39 Fog (MINFILE 093M 125) claims were staked by Sicintine Mines Ltd. immediately to the west. A program of geological mapping, geochemical sampling and trenching was performed at this time.
In 1978, St. Joseph Explorations Ltd. completed a program of rock sampling and geological mapping on the Fog and Peak claims. The average of five chip samples taken from the vein yielded 0.27 per cent molybdenum and 0.11 per cent copper over an average true width of 3.9 metres (Assessment Report 7116).
In 2013 and 2014, Vale Exploration Canada Inc. completed a program of geological mapping, geochemical sampling and a 3278.0 line-kilometre airborne magnetic survey on the area as the S2 property. In 2017, an induced polarization and magnetotellurics survey was completed on the property.
In 2014, a channel sample (RX401559) from a white siliceous dike with disseminated pyrite and quartz-potassium feldspar-sulphide veins yielded 0.046 per cent molybdenum over 0.65 metre, whereas a grab (RX399548) sample and a chip (RX399547) sample from outcrops of quartz monzonite with mineralized quartz veining yielded 0.086 and 0.064 per cent copper with 0.051 and 0.132 per cent molybdenum, respectively (Assessment Report 35139). A float boulder sample (RX399539) assayed 0.218 per cent molybdenum (Assessment Report 35139).
