A magnetite-bearing pyroxenite pluton of the Late Triassic to Early Jurassic Copper Mountain Plutonic Suite has intruded fine-grained andesitic rock of the Upper Triassic Stuhini Group. The largely uniform dark-green, massive, crystalline pyroxenite plug appears to be an oval shaped body (in plan), approximately 5 by 2.3 kilometres in area. It was observed to have a distinct layered structure by grain size with a roughly northeast strike and a dip of 30 degrees to the southeast.
The pyroxenite is mainly composed of green augite which is replaced in part by magnetite and minor amounts of olivine, biotite and pyrite. Scattered fine-grained pyroxene veins up to 4 centimetres in width occur with magnetite and feldspar with selvedges of pink potash feldspar. Minor stringers of pink potash feldspar and epidote are also observed.
The magnetite occurs interstitially as very fine to very coarse grains often forming irregular blebs. Two magnetite veins from 30 to 40 centimetres wide were observed and found to be rich in pyrite and small amounts of chalcopyrite. The magnetite is uniformly titaniferous containing up to four per cent titanium oxide. The titanium is presumed to be in the form of ilmenite.
An 18 metre chip sample near the centre of the plug assayed 6.51 per cent magentite iron and 0.83 per cent titanium (104G/13 Fe1). Another chip taken over 15.5 metres contained 8.25 per cent magnetite iron and 0.80 per cent titanium (Annual Report 1966, page 23). One 60 centimetre zone yielded 84 per cent magnetite but this type of mineralization is uncommon.
Work History
An aerial magnetometer survey over the area in 1964 revealed several anomalies and a group of 82 claims was located in 1965, The locators sold the property to Stikine Iron Mines Ltd. Work by the company during 1965 included 3810 metres of trenching, about 3 acres of stripping by bulldozer, and a 47.5 kilometre magnetmeter survey along 56 claims.
In 1988, Integrated Resources Ltd collected 63 soil samples and conducted 6.6 kilometres of geophysical surveying including magnetometer, Max-Min EM and VLF-EM (Assessment Report 18862). The work was conducted on the Iron 1 and 2 claim. The grid was located near the centre of an intense aeromagnetic high. Pyroxenite outcrop was observed in the baseline vicinity, while further north volcanic rock was observed. Syenite float was also observed.