The Joan copper occurrence is situated in the Joan claim group, 8 kilometres west-southwest of the junction of Delano Creek and Racing River and 6 kilometres northeast of Mount Roosevelt in the Muskwa Ranges of the Northern Rocky Mountains (Assessment Report 4639, Map 6).
The occurrence is in a region known as the Muskwa Anticlinorium, a major north-northwest–trending structure characterized by moderate folding and thrust faulting. The structure consists of Middle Proterozoic (Helikian) rocks of the Muskwa Assemblage, as well as Paleozoic rocks (Geological Survey of Canada Map 1343A; Geological Society of America, Geology of North America, Volume G-2, pages 111, 639). All belong to Ancestral North America (Geological Survey of Canada Map 1713A). Northeast- to northwest-trending Proterozoic diabase dikes are common in the region.
The Joan and JN group of claims is underlain by the Aida and Tuchodi formations of the Muskwa Assemblage, and by rocks of the Cambrian Atan Group (Assessment Reports 2641, 4639; Geological Survey of Canada Memoir 373). The mineralization appears to be confined to Aida Formation rocks, which in this area consist of limy and dolomitic slaty argillite and siltstone, sandstone, dolostone and limestone. Bedding strikes northwest and dips moderately southwest. A few outcrops of diabase dikes are present on the property, striking between north and east.
Small amounts of copper mineralization have been found. The occurrence is centred on the best showing, on the JN 5 claim (Assessment Report 4639, Map 6; Property File - updated claim map). Here, quartz-ankerite breccia veins, in strongly altered argillite associated with a diabase dike, are mineralized with blebs of chalcopyrite, minor pyrite and malachite. Roughly 1 kilometre to the west, in the Joan 2 and 19 claims, there are two other, small occurrences of chalcopyrite, malachite and pyrite in quartz sandstone and chloritic schist (Assessment Report 4639, Map 6).
Work History
In 1970, a 172.8 line-kilometre airborne magnetic survey was completed on the behalf of R.W. Shaw on the area as the Joan and BE claims. In 1973, Yamoto Mining and Smelting Ltd. completed a program of geological mapping and a 16.7 line-kilometre ground magnetic and electromagnetic survey on the Joan claims. In 1979 and 1980, Halferdahl & Associates Ltd. completed a regional program of soil sampling on the area as the Tuchodi property.
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 (Assessment Report 28281).