The geology and economic potential of the Athabasca Basin in Alberta

CIM Bulletin, Vol. 80, No. 898, 1987

JOHN WILSON, Geological Survey Department, Alberta Research Council, Edmonton, Alberta

The unconformity beneath 75 per cent or over 6000 km? of the Athabasca Basin in Alberta lies within economically exploitable depths. The basement beneath this unconformity consists of an extension of the Wylie Lake Pluton, locally faulted and containing areas ofmylonitic rocks. While the rocks of the Wylie Lake Pluton are not promising host rocks for uranium ore deposits, the areas ofmylonites, graphitic rocks and possible remnants of granite gneiss would bear closer examination. One area of mafic mylonites shows a weathering zone enriched in Si, Ca, Na, Pb, Ni, Ba, Co, Sr, Zn and U in addition to reported values of 0.08 oz/ton gold. This zone occurs beneath 800 m to 900 m of Athabasca Group sediments, but similar rock types are present beneath much thinner cover elsewhere. Detailed geophysical exploration is required over the area of thinner Athabasca Group rocks to define more precisely the areas of promising basement rock type.

Keywords: Mineral exploration, Economic geology, Athabasca Basin, Uranium deposits, Alberta, Geochemistry.