The Peace River Formation is thick on average. The formation has different extents at different stages, with the
Paddy Member present only in the
Peace River Country in
northern Alberta south of
Clear Hills, while the
Cadotte Member and the
Harmon Member occur in both
Alberta and north-eastern
British Columbia.
Physiography The Peace River Lowland, a landform region in the
Alberta Plateau, is a gently rolling lowland without clearly defined outer boundaries extending east of the
Rocky Mountains on both sides of the
Peace River and sloping downward to the north and east. The higher hills in the foothills east of the
Rockies in northeastern
British Columbia have elevations of about 1000 m and the plains west of
Lake Athabasca are about 300 m above sea level. The lowland's
Quaternary sediments of the former lake bottom of Glacial Lake Peace are underlain by Upper and Lower
Cretaceous sedimentary rocks mainly shales of the Shaftesbury formation and sandstones of the Dunvegan and Peace River formations. The
Peace River and its immediate tributaries have incised almost 200 meters into the sediments and into the Cretaceous bedrock in the western section but only about 70 meters in the east side further north around
Fort Vermilion. On the basis of topography and landscape pattern, the area may be subdivided into four local physiographic units: the Peace River Lowland, Otter Lakes Upland, Utikuma Lake Upland, and Clear Hills Upland. The Peace River Lowland is located in the central part of the area and is dissected by the
Peace River. The Otter Lakes Upland in the northeast is a southern extension of the Buffalo Head Hills. It has a rugged
moraine topography with steep slopes and isolated hills. Elevations above sea level range from to . The Utikuma Lake Upland in the southeast also ranges from to . The Clear Hills Upland in the west ranges from to . ==Relationship to other units==