The Tucho occurrence is situated on a northwest-facing slope, approximately 9.5 kilometres west-southwest of the western end of Tucho Lake, in the Stikine Ranges of the Cassiar Mountains in the Northern Rocky Mountains (Assessment Report 3499, Map 1).

Regionally, the area lies within a narrow belt of volcanic rocks, between the Lower Cretaceous Cassiar Batholith to the north (in the Cassiar terrane), and the Lower Jurassic granodioritic Pitman Batholith to the south. The latter intrusion and the volcanics belong to the Quesnel terrane (Geological Survey of Canada Map 1713A). The volcanics are part of the Upper Triassic Takla Group (Shonektaw Formation), composed mainly of mafic to intermediate volcanic and volcaniclastic rocks of island arc origin (Geological Survey of Canada Map 1712A). The geology is shown in more detail in Geological Survey of Canada Map 42-1962; however, the units are designated differently and have since been revised.

The mineralization is hosted by augite porphyry volcanics (Assessment Report 3499). The area is structurally complex due to numerous intersecting faults and shear zones and has been affected by widespread argillic, sericitic and limonitic alteration. This area is surrounded by a broader area of chloritic alteration, accompanied by magnetite and epidote. Pyrite appears to be more abundant towards the margin of the main altered area, suggesting a pyrite halo.

Copper mineralization is apparently centred on a prominent brecciated zone, trending 280 degrees, in the altered augite porphyry volcanics (Assessment Report 3499). Sulphides, presumably mainly chalcopyrite, are disseminated in the rock and in fracture veinlets.

In 2012, a subcrop grab sample (1725212) of silicified augite basalt with quartz-calcite-chalcopyrite veins from the Tucho occurrence area assayed 0.515 per cent copper (Assessment Report 34267).

Work History

In 1971, an induced polarization and resistivity survey was completed over 7.6 line-kilometres on behalf of Cordilleran Engineering Limited.

In 2011 and 2012, Teck Resources Ltd. completed programs of prospecting, geochemical (rock and silt) sampling and a 6411.9 line-kilometre airborne electromagnetic (ZTEM) survey on the area as the Pitman property.