ABSTRACT

Over 30,000 feet of pre-Devonian sediments are exposed in the Front and Main Ranges of the Canadian Rocky Mountains between Jasper, Alberta and Pine River, British Columbia. The Proterozoic Miette Group, estimated to be 6,000 to 15,000 feet thick, is composed of argillite, schist, conglomerate, quartzite and dolomite, locally divisible into map units. The Byng Formation is a new name proposed for a Proterozoic dolomite unit. Paleozoic sediments overlie the Proterozoic with regional unconformity. The Lower Cambrian consists of up to 7,000 feet of quartzite, conglomerate, shale and dolomite separated into McNaughton, Mural and Mahto Formations. The Middle Cambrian is composed of shale, limestone and dolomite, up to 5,000 feet thick, separated into Hota-Adolphus, Tatei-Chetang, Titkana, Pika and Arctomys Formations. The Upper Cambrian Lynx Formation, up to 4,000 feet thick, consists of limestone and dolomite which becomes argillaceous to the north and merges into a gross Cambro-Ordovician limestone-shale unit. To the south, 3,000 feet of Lower Ordovician sediments are separated into a lower Chushina Formation of dolomite and argillaceous limestone and an upper quartzite unit for which the name Monkman Quartzite is proposed. The Middle-Lower Ordovician Skoki Formation, 1,700 feet thick, consists of dolomite and sandstone and is unconformably overlain by 700 feet of Upper Ordovician Beaverfoot Formation. The Lower Paleozoic section is regionally truncated by the basal Devonian unconformity.