The D 81 copper occurrence is located approximately 2 kilometres southeast of a major tributary of the Gataga River and approximately 7 kilometres west-southwest of Churchill Peak in the mountainous Muskwa Ranges of the Northern Rocky Mountains (Assessment Report 2869, Map 4).

The occurrence is in a region known as the Muskwa Anticlinorium, a major north-northwest–trending structure characterized by thrust faults and moderate folding. Rocks as old as Middle Proterozoic (Helikian) outcrop in the structure, along with Paleozoic rocks (Geological Survey of Canada Map 1343A; Geological Society of America, Geology of North America, Volume G-2, page 639). All belong to Ancestral North America (Geological Survey of Canada Map 1713A). The Middle Proterozoic rocks are pre-Windermere Supergroup, and are known as the Muskwa Assemblage (Geological Society of America, Geology of North America, Volume G-2, page 111). Proterozoic diabase or gabbroic dikes are common in the region.

The D group of claims is underlain mainly by the Aida Formation, with Gataga Formation rocks confined to the west and south, both of the Muskwa Assemblage (Geological Survey of Canada Memoir 373, Paper 67-68). The Aida Formation consists of dark-grey, fine-grained, laminated calcareous or dolomitic shale and siltstone, and mudstone. Locally the strata strike north and dip 5 to 30 degrees west. more than 30 diabase dikes, typically 5 metres wide, have been mapped in the claim group. They strike north-northwest and dip approximately 85 degrees west, although a few have a transverse, east strike. Fracture-controlled quartz-carbonate veins are commonly associated with the dikes, but few are mineralized.

The D 81 occurrence is centred on a mineralized, banded, quartz-carbonate (some ankerite) vein (Assessment Report 2869). The vein strikes north and fills a fracture in a sheared diabase dike. It is 6 metres long and 15 centimetres wide. Pods of high-grade chalcopyrite are distributed evenly along its length. A visual estimate of the overall grade was reported at approximately 10 per cent copper (Assessment Report 2869). Secondary malachite is also present.

Work History

In 1970, Fortune Channel Mines Ltd. completed a program of geological mapping on the area as the D group of claims. Also at this time, Windermere Exploration Ltd. completed a program of geological mapping, hand trenching and rock sampling on the area immediately south of the occurrence as the Bronson claim group.

In 1981 and 1982, Coppex Syndicate completed a program of geological mapping and geochemical (rock and soil) sampling on the area as the BE and MO claim groups.

In 2005, Twenty-Seven Capital Corp. completed a regionally extensive program of geochemical (rock, silt and soil) sampling and a 9002.0 line-kilometre airborne magnetic survey on the area as the Muskwa property.

In 2012, a remote sensing and geophysical data interpretation program was completed on the area as part of the regionally extensive Northern IOCG property.