green shale and non-marine red shale, the Beaver Mines Formation with shale and chlorite sandstone and the Mill Creek Formation with pyroclastic flow sediments, related to Mesozoic volcanism in the Canadian Rockies. North of the Calgary-Banff highway, the Gladstone and Beaver Mines Formation become carbonaceous and coal-bearing. A significant unconformity separates the Blairmore Group from overlying rocks. During the Cenomanian and Albian, the connection with the Arctic Ocean was nearly severed, creating the Mowry sea, which developed its own endemic group of ammonites. Fossils across western Canada with both exotic and endemic fish scales and ammonites indicates that the Gulf of Mexico flooded the area from the south. The sea filled with fine sediments of the Colorado Group concurrent with the deposition of clastic and volcanic sediments in the Mill Creek Formation. The Joli Fou shale and Viking (Bow Island) sand, plus lower Colorado Group shales cover the Blaimore Group in southern Alberta. The Colorado Group (known locally as the Alberta Group) occupies the Cordilleran foothills with the 1700-foot thick Blackstone Formation near Nordegg, which holds silty and platy shales, together with the Cardium Formation marine sandstone and shales, and the Wapiabi Formation which reaches up to 2000 feet thick with mudstone, ironstone and ammonite fossils. Cenozoic (66 million years ago-present) During the Cenozoic sedimentation continued in the Western Canada Sedimentary Basin, spanning Alberta. The Paskapoo Formation deposited near the Rockies, together with the Ravenscrag Formation in the southern Cypress Hills Formation. The Paskapoo Formation reaches up to one kilometre thick and holds fossils of gliding mammals and early pangolins. References