The Gataga 9,11 copper occurrence is located approximately 11 kilometres north of the Gataga River and 9 kilometres west-southwest of Churchill Peak in the mountainous Muskwa Ranges of the Northern Rocky Mountains (Assessment Report 2639, Map 1).
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 Gataga claim group is underlain by the Aida and Gataga formations of the Muskwa Assemblage (Geological Survey of Canada Memoir 373, Paper 67-68; Assessment Reports 2639, 10960). The Aida Formation consists of interbedded dolomitic siltstone, argillaceous limestone, slate and argillite. The Gataga Formation comprises thinly bedded slate and slaty mudstone and siltstone. The strata strike north-northwest and dip gently to moderately west. Slaty cleavage dips westwards more steeply than bedding. Subhorizontal, unconformably overlying dolostone and quartzite of the Cambrian Atan Group lie at the southwestern extremity of the claim group.
A number of diabase dikes intrude the Proterozoic rocks. They dip steeply westwards and generally strike northwest, though some strike north or northeast. Some contact metamorphism is present. Faults and shear zones in the area have similar attitudes to the dikes, and many occur along dike margins.
The Gataga 9,11 occurrence is centred on Showing No. 2 (Assessment Report 2639), also called the Gataga North zone (Geology, Exploration and Mining in British Columbia 1971). A series of short, discontinuous veins occur along the sheared margins of diabase dikes, and in fracture zones in the dolomitic slate country rock in their vicinity. The veins are oriented north to northeast and dip approximately 50 degrees east. They have a strike length of approximately 75 metres and range from 0.3 to 3 metres in width. The veins consist of quartz, calcite and dolomite, and are moderately well and irregularly mineralized with chalcopyrite and pyrite in masses up to 30 centimetres wide in the central portion of the veins. The sulphides are locally weathered to a limonitic gossan, accompanied by malachite and azurite. The grade of the strongest chalcopyrite was visually estimated at between 2 and 5 per cent copper (Assessment Report 2639).
One vein is sharply truncated by a dike; this and other evidence at this showing indicates that the dikes are generally younger than the copper-bearing veins (Geology, Exploration and Mining in British Columbia 1971).
A second quartz vein, 0.3 metre wide, with minor chalcopyrite is reported near the Gataga 13 and 15 eastern claim border, approximately 500 metres south-southeast of the main No. 2 zone.
A third zone of minor mineralization is reported on the BL178 claim, located approximately 4 kilometres to the west of the Gataga North zone, and comprises a 0.6 by 3.0 metre zone of quartz stringers hosting minor chalcopyrite in a shale and/or siltstone.
In 2005, a chip sample (B374301) from the Gataga 9-11 occurrence yielded 1.66 per cent copper over 2 metres (Assessment Report 28281).
Work History
In 1970, Windermere Exploration Ltd. completed a program of geological mapping, hand trenching and rock sampling on the area as the Bronson and Gataga claim groups. Also at this time, Fortune Channel Mines Ltd. completed a program of geological mapping on the area immediately east of the occurrence as the D group of claims and Beaumont Resources completed a program of geological mapping on the BL group of claims to the west of the occurrence.
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.
