The Gossan Creek prospect is situated on the west side of the Upper Kitimat River valley, 29.5 kilometres northeast of Kitimat, B.C.
The area is underlain by several phases of the Upper Cretaceous- Tertiary Coast Plutonic Complex consisting of gabbro, hornblende- biotite diorite, biotite granodiorite, soda granite, and muscovite granite. A roof pendant of Hazelton volcanics occurs to the northwest. Northwest trending dykes ranging in composition from diorite to quartz monzonite cut all rocks.
Pyrite, molybdenite, and chalcopyrite occur in narrow quartz veinlets and to a lesser extent as fracture coatings and as disseminations. In Gossan Creek, three weakly mineralized stockworks, 15 to 50 metres wide, occur over a 750 metre length and a 450 metre vertical distance, within a 1050 by 450 metre east trending plug of quartz-feldspar porphyry. Silicification, feldspathization, and sericitization are structurally controlled and associated with molybdenum mineralization.
Potassic alteration in quartz-feldspar porphyry at Gossan Creek is related to north-south trending, subvertical shears. In the porphyry matrix, potassic alteration occurs mostly as re-crystallization and overgrowth of potassium feldspar. Red-brown biotite and magnetite crystallization is less abundant. Early mafic and ‘A’- type quartz-potassium feldspar veins are most common in the areas of the shears. Veins in the porphyry have sparse, very fine-grained (<1 mm) pyrite, chalcopyrite, and molybdenite mineralization.
All of the rocks examined in Gossan, Lamp, and Mantle creeks have undergone potassic alteration. Thus, the core potassic alteration zone of the Mantle hydrothermal system exists as a single zone that extends for a north-south distance of at least 2.9 km from Gossan Creek to Mantle Creek. The main Gossan Creek soil-molybdenum anomaly is located directly atop altered and mineralized quartz-feldspar porphyry that forms the bluffs. It is deemed to have developed in place from weathering of underlying mineralized material.
Chip sampling of the mineralized zones gave weighted averages of 0.019 per cent molybdenite and 0.029 per cent copper over three metres. The best interval overall is 50 metres of 0.03 per cent molybdenite (Assessment Report 14011).
Work History
During the mid-1960’s Southwest Potash (Amax) completed programs of geological mapping and geochemical (rock, soil and stream sediment) sampling on the area. In 1979, Amax completed a further program of geological mapping and geochemical (rock and soil) sampling on the area. In 1984 and 1985, Abo Oil Corp. completed programs of geochemical (rock, soil and silt) sampling. In 1986, a ground electromagnetic survey was completed.
In 2016, the Mantle Property covering the Mantle Creek (Minfile 103I 109) and Gossan Creek (Minfile 103I 103) prospects, was staked by J. Ostler. Alteration mapping and interpretation of Mo soil anomalies was conducted on the property as well as gathering 5 pan concentrates from Gossan, Lamp, Mantle and South creeks (Assessment Report 36182).
In 2018, Zenith Exploration Inc. had airborne magnetic and radiometric surveys flown over the Mantle property. Three generations of major linear structures are clearly visible via the distribution of total magnetic intensity across the property area characterizing different stages of intrusive activity and later cross-cutting mafic dykes. Around the quartz-feldspar porphyry at Gossan Creek, a phyllic alteration zone has almost completely overprinted the potassic zone and produced a potassium/thorium radiation low that has a roughly circular shape around the quartz-feldspar porphyry at Gossan Creek (Assessment Report 38162).
