The P 75 copper occurrence is located in the headwaters of the Gataga River, approximately 12.5 kilometres south of Churchill Peak in the mountainous Muskwa Ranges of the Northern Rocky Mountains (Assessment Report 2868, Map 4).
The occurrence is in a region known as the Muskwa Anticlinorium, a major north-northwest–trending structure characterized by large, folded thrust sheets that expose rocks as old as Middle Proterozoic (Helikian), as well as 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).
Northeast– to (more commonly) north-northwest–trending, steeply-dipping diabase or gabbroic dikes are common in the region. These Proterozoic intrusions were structurally controlled; their presence and orientation are closely related to regionally important fault and fracture zones in the Proterozoic sedimentary rocks.
The area around the P 75 showing is underlain mainly by dark-grey, locally slaty calcareous siltstone and shale of the Aida Formation of the Middle Proterozoic Muskwa Assemblage (Geological Survey of Canada Memoir 373; Geological Society of America, Geology of North America, Volume G-2, page 111). The strata generally strike north and dip gently from 5 to 30 degrees west. At least 10 diabase dikes intrude the area, striking north-northwest and dipping 85 degrees west to 90 degrees. They average 5 metres in thickness, and some can be traced for approximately 250 metres.
Typical of the copper occurrences in the region, the P 75 is centred on a system of multiple, mineralized quartz-carbonate veins within a broad shear or fault zone hosting a number of diabase dikes. The mineralized zone, striking approximately 340 degrees and dipping 80 degrees west, is 7.5 metres wide and is exposed for 60 metres. Individual veins are between 2.5 and 30 centimetres thick and are present in the dikes as well as the sedimentary rocks, and along their contact. They are not continuous anywhere for more than 2 metres before pinching out. The mineralization is weak and erratic, consisting of blebs of chalcopyrite and lenses of massive pyrite, and secondary malachite. A visual estimate of this zone was given as up to 1 per cent copper (Assessment Report 2868).
Another, reportedly better-mineralized, vein system is present approximately 1.2 kilometres to the south at the P 12 (MINFILE 094K 045) occurrence.
Work History
In 1970, Fortune Channel Mines Ltd. and Beaumont Resources Ltd. completed a program of prospecting, geological mapping, trenching and rock sampling on the area as the P property. Also at this time, Windermere Exploration Ltd. completed a program of geological mapping and rock sampling on the area immediately west of the occurrence as the Chopper claim group and Acroll Oil and Gas Ltd. completed a program of geological mapping on the area immediately north of the occurrence as the Andrew claims.
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.
