REFINEMENT OF THE STRATIGRAPHIC FRAMEWORK FOR THE REGIONAL C DEPOSITIONAL UNIT OF THE MCMURRAY FORMATION AND IMPLICATIONS FOR THE EARLY TRANSGRESSION OF THE ALBERTA FORELAND BASIN, CANADA

摘要

The Lower Cretaceous McMurray Formation in Alberta and Saskatchewan, Canada, comprises a series of depositional units (DUs) consisting of stacked parasequences bounded by flooding surfaces and incised by fluvioestuarine channel belts. The fluvio-estuarine channel belts of the McMurray Fm have been the focus of numerous studies whereas the regional DUs have received substantially less attention. Of the regional DUs, Regional C (equivalent to the middle McMurray) is the most understudied, yet this interval records the history of the McMurray Formation between deposition of fluvial strata in the lower McMurray and marine facies in the upper McMurray and overlying Clearwater Formation. Determining the history of the Regional C DU is fundamental for accurately reconstructing the stratigraphic evolution of the McMurray Fm and, by extension, the early evolution of the Alberta Foreland Basin.