The effect of paleotopography on the late Albian and Cenomanian sea-level record of the Canadian Cretaceous interior seaway

摘要

In western Canada, a major paleoenvironmental change at the Albian-Cenomanian boundary is related to a eustatic sea-level rise overprinted by a relative sea-level fall in conjunction with preexisting topography within the basin. This paper shows the lateral variability of sedimentology, paleoecology, and biostratigraphy of the latest Albian to Cenomanian interval along the Canadian western margin of the Cretaceous interior seaway. This paper (1) provides an integrated depositional and paleoecological examination of the Albian and Cenomanian lithologic units in the northern Western Interior Seaway; (2) demonstrates the effect of antecedent paleotopography within the basin at the time of the transgression; (3) documents the variability in sedimentary facies and paleoecology controlled by paleorelief; and (4) demonstrates the diachroneity, lateral extent, and extremity of the multiple unconformities controlled by this paleorelief.