LOWER CRETACEOUS HEAVY OIL ACCUMULATIONS
Dr. Laurence W. Vigrass, a native of Melfort, Saskatchewan, received his early education at the nearby community of Pothlow. He attended the University of Saskatchewan and received a B.E. (geological engineering) in 1951 and on M.Sc. in 1952. He joined the California Stan-Jard Company, but left in 1954 to do further graduate work at Stanford University, receiving a Ph.D. in 1961 . From 1958 to 1965 he was with Imperial Oil Limited in Calgary, and wrote this paper while attached to their Heavy Oil Group. In June, 1965, he joined Western Resources Consultants Ltd. of Calgary.
The Upper Mannville unit commonly consists of interblended marine and non-marine sands and shale's, but in northwestern Alberta the unit consists of marine shales of the Spirit River Formation. A thick tongue of marine shale (Clearwater Formation) extends eastward into the Athabasca area below sandy Grand Rapids beds. Correlation of Upper Mannville rocks to the southeast is difficult, but in the Cold Lake area a thick sandy depositional cycle (Mannville "C" of this paper) appears to be approximately correlative with the Clearwater Formation. In the Lloydminster region, tongues of marine sedimentary rock occur in the lower part of the Upper Mannville unit. PEACE IATHABASCAI I LLOYD . I MAP RIVER . WABASCA COLD LAKE MINSTER UNIT Most of the Upper Mannville oil occurs in the Grand Rapids Formation at Wabasca, in the thick "C" unit and younger Mannville sands at Cold Lake, and in the Sparky and General Petroleums sands of the Lloydminster region
Alberta, Athabasca, Deposits, Lloydminster, Lower Cretaceous Origin of, Southern Alberta, syncline, Upper Mannville, Oil, Oils, Sand, Shale, Water, Waters