Bulletin 022

Bulletin 022

BUL 022

Surficial Geology of the Foremost-Cypress Hills Area, Alberta

Author(s) Westgate, J.A. Date 1968-01-01

This study was undertaken to determine the distribution, thickness, composition, and origin of the Pleistocene deposits of the Foremost-Cypress Hills area to provide maps to aid in developing economic resources, especially groundwater and constructional materials, and to establish the Pleistocene stratigraphic succession.

The Foremost-Cypress Hills area is divided into six physiographic units: Cypress Hills Plateau, upland areas, till plain, lacustrine plains, river channels, and canyons. The South Saskatchewan River drains the northern part of the area, and the Milk River drains the southern part. A small internal drainage basin is centred on Lake Pakowki.

Glaciation modified the preglacial physiography of the upland areas to a lesser extent than that of the lower tracts. The preglacial valleys in places contain more than 250 feet of glacial drift. Rivers in the Lethbridge and Medicine Hat valleys drained the map area in preglacial times, both occupied broad, open valleys and flowed northeastwards.

End moraine, including washboard moraine, is the most widespread glacial landform. Others present include ground moraine, hummocky disintegration moraine, linear disintegration ridges, drumlins and drumlinoid ridges, kames, eskers, and flutings. Proglacial landforms in the area include outwash aprons, a loess plain, glacial lake basins, meltwater channels, and spillways.

Westgate, J.A. (1968): Surficial geology of the Foremost-Cypress Hills area, Alberta; Research Council of Alberta, RCA/AGS Bulletin 22, 137 p.