Abstract

Informal rock stratigraphic units have been established for the area. They consist of the Marlboro, Raven Creek, Obed, and Drystone Creek tills of Cordilleran provenance, and the Marsh Creek, Edson, and Mayberne tills of Canadian Shield or Laurentide source. Three different gravel units of Tertiary–Quaternary age underlie glacial deposits of the area and are here called the Tableland, Lowland, and Buried Valley gravel, in order of decreasing age.Evidence for four and possibly five glacier advances has been recognized. The oldest is inferred by fragmentary evidence of an 'Early' Cordilleran till. The second, represented by the Marsh Creek till, is the initial and greatest advance of Laurentide ice into the area. In the third both Cordilleran and Laurentide glaciers advanced and met. The Cordilleran ice is recorded by the Marlboro and Raven Creek tills, and the Laurentide by the Edson and Mayberne tills. The fourth glacial advance is documented by the Obed till of Cordilleran source. The Hinton terraces were formed during retreat of this glacier. The last glacier advance is indicated by the Drystone Creek till present in small valleys at the mountain front.Although radiocarbon dates are not available, the Marlboro, Obed, and Drystone Creek Cordilleran ice advances may represent the Early, Middle, and Late Stages of the Pinedale Glaciation (classical Wisconsin) of the Rocky Mountain area of the United States of America. Broadly correlative Cordilleran glacial advances occurred in the Banff area and the Williston Lake area of British Columbia.

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