Report 99

Author(s) Date 2020-04-20

Lithostratigraphic correlation and mapping of formations and units within the Elk Point Group aims to provide updated information on their extent and distribution within the province of Alberta. Together with detailed net-evaporite mapping of three evaporite minerals, halite, anhydrite, and gypsum, within evaporitic successions, these data provide new representations of the paleogeography of these units across the province. Paleogeographic maps of the Keg River and Prairie Evaporite and Muskeg formations provide new details on the location of the La Crete sub-basin in northern Alberta, and the distribution and nature of Keg River Formation buildups and the overlying evaporite strata within this depositional realm. The net-evaporite mapping provides a robust picture of the distribution of evaporites within the province, and allows for a detailed characterization of heterogeneities within halite-bearing successions, such as interbeds comprising anhydrite, carbonate, and shale. Understanding the degree of nonhalite interbedding has implications for the placement of future caverns within halite successions of the Elk Point Group. Additionally, net-evaporite mapping reveals a number of local-scale zones of evaporite karstification that differ in age from the regional, basin-margin, Prairie Evaporite halite dissolution scarp. Evidence is provided for a top-down advancement of evaporite karstification within all but one recognized zone of karstification.

Hauck, T.E. (2020): The Elk Point Group of Alberta: insights into paleogeography, evaporite karstification, and salt cavern potential based on net-evaporite mapping; Alberta Energy Regulator / Alberta Geological Survey, AER/AGS Report 99, 60 p..