Geology of the Alexander-Wylie Lakes District, Alberta

The geology of 486 square miles (1254 square km) of Precambrian Shield in northeastern Alberta is presented on four colored map sheets at a scale of 2 inches to 1 mile.

Sixteen main rock types and several sub-phases are distinguished on these maps. Their characteristics in outcrop and in hand specimen are described, and modal and chemical analyses of representative standard samples are presented.<>

Anomalous radioactivity was found in granitoid bodies, especially in the coarse grained and pegmatitic phases, over large areas north of Fidler Point.

The gneissic-granitoid basement complex is unconformably overlain by Athabasca Formation sandstones at several points along the shoreline of Lake Athabasca. A well-developed regolith has been mapped beneath the Athabasca sandstone at Greywillow Point.

The area was glaciated during the continental glaciation of Pleistocene Age and features of glacial erosion and deposition are common.