The Marb occurrence is located at an elevation of approximately 1450 metres on a southwest-facing slope, approximately 300 metres southwest of the west end of Stumbles Lakes.
The Promontory Hills-Craigmont mine area is underlain by a complex northwest-trending, steeply dipping volcanic pile of Upper Triassic Nicola Group rocks, bounded to the north by the Upper Triassic to Lower Jurassic Guichon Creek Batholith and unconformably overlain by the Upper Cretaceous Kingsvale Group. Much of the area is covered by thick gravel overburden. Regional faults trend northwest.
The occurrence area is primarily underlain by medium-grained potassium-feldspar–rich quartz diorite designated as the Border phase of the Guichon Creek Batholith (Map 30). A jointing system and faint steeply dipping gneissosity are characteristic of this unit. Rare pyroxene-rich zones are also present. To the south the area is underlain by Upper Triassic Nicola Group andesite, tuffs and limestone. Alteration includes chloritization and epidotization.
At the contact of the intrusive and the Nicola Group rocks, a wide zone of diorite breccia is developed. Two types of mineralization are found in the breccia zone. The first is disseminated magnetite, pyrite and pyrrhotite in hornfelsed volcanic fragments. Secondly, near strong chloritized shears, chalcopyrite, pyrite and pyrrhotite occurs as fine disseminations and slender veins.
Similar mineralization is reported approximately 750 metres to the northeast of the previous zone.
Later work (2015) identified a zone of magnetite-chalcopyrite skarn and a malachite-stained sheared zone in a diorite.
Work History
In 1958, Northwestern Exploration completed a program of soil sampling, geological mapping and 50.1 line-kilometres of ground magnetic surveys on the area as the CJS property. Also at this time, Craigmont Mines Ltd. completed a 11.6 line-kilometre ground magnetic survey on the area immediately east of the occurrence as the Hec North property and Rio Canex Ltd. completed a program of soil sampling, geological mapping and 7.3 line-kilometres of ground geophysical surveys on the area immediately south of the occurrence as the KL claims.
In 1960, a 64.0 line-kilometre ground induced polarization survey was completed on the area immediately south of the occurrence as the Lil and KL claims. In 1965, Torwest Resources Ltd. completed a program of geological mapping and diamond drilling, totalling 2438.4 metres, on the area as the Marb and Apache claims. No drilling results are known. In 1969, Torwest completed a 56.6 line-kilometre ground magnetic and electromagnetic survey on the Marb claims.
In 1994, Better Resources Ltd. completed a ground magnetometer survey on the area immediately south of the occurrence as the Huff 1-2 claims. The survey identified a magnetic anomaly on strike with projections of a limy horizon previously intersected by drilling (1978) to the east.
In 2000, Ahura Mining Ltd. completed a program of geological mapping and geochemical (rock and soil) sampling on the area as the Gord 1-10 claims.
In 2012, Huldra Silver Inc. completed a 903 line-kilometre airborne geophysical survey on the area as the Thule property. This work isolated six magnetic anomalies (A through F) with the potential for magnetite skarn development, similar to the nearby Craigmont (MINFILE 092ISE035) deposit.
In 2015, Nicola Mining Inc. completed a program of rock and soil sampling on the area as the Thule Copper-Iron property. Two outcrop grab samples (290515-THU-004 and -005) from this zone assayed 0.733 and 0.218 per cent copper, respectively (Assessment Report 36141).
In 2016, Nicola Mining Inc. completed a program of prospecting, rock sampling, geological mapping and five diamond drill holes, totalling 1063.7 metres, on the Thule Copper property.
In 2017, Nicola Mining Inc. and Clibetre Exploration Ltd. completed a program of geological mapping; a 27.0 line-kilometre induced polarization survey, a 24.5 line-kilometre airborne magnetic survey, 29 rotary drill holes, totalling 392.0 metres, and 5 diamond drill holes, totalling 2994.7 metres on the Thule Copper property.
In 2018, Nicola Mining Inc. completed a 9.0 line-kilometre ground magnetic and induced polarization survey; 70 percussion drill holes, totalling 1540.0 metres, and 16 diamond drill holes, totalling 6438.5 metres, on the area as the Craigmont property. A rock sample from the Marb occurrence yielded 0.718 per cent copper (Assessment Report 38679).
In 2019, Nicola Mining Inc. completed a program of soil sampling and five diamond drill holes, totalling 3649.0 metres, on the area as the New Craigmont property.