Bulletin 049

Bulletin 049

BUL 049

Geology of the Athabasca Group in Alberta

Author(s) Wilson, J.A. Date 1985-01-01

Four formations of the Helikian Athabasca Group are present in Alberta. They are distinguished by variations in grain size, clay content and sedimentary structures. From the base, they are the Fair Point, the Manitou Falls, the Wolverine Point and the Locker Lake Formations. The Wolverine Point Formation is informally subdivided into an upper and a lower member.

Petrographic studies of the Athabasca Group support the formational divisions and reveal a complex history of diagenesis. The diagenesis affected the porous units within the Athabasca Group and imparted to them a distinctive clay mineral composition that can be broadly elated to the lithostratigraphy. Thin section examinations reveal the uffaceous nature of many siltstones and shales of the upper member of the Wolverine Point Formation. These tuffs are both vitric and ash flow and are derived from a silica-over saturated volcanicity. The tuffs of the upper member of the Wolverine Point Formation show evidence of having been deposited under nearshore marine conditions; the remainder of the Athabasca Group was deposited in a fluvial setting.

Areas of potential interest for uranium exploration occur where the Athabasca Group is less than 200 m thick and where it is present as outliers. Potential for economic lead-zinc mineralization is also present, associated with zones of fracturing in the sandstone.

Wilson, J.A. (1985): Geology of the Athabasca Group in Alberta; Alberta Research Council, ARC/AGS Bulletin 49, 85 p.