CHARACTERIZATION OF SEDIMENTARY BEDFORMS OF COLORADO GROUP MUDSTONES

In this study, the Second White Specks (2WS) Formation, part of the middle Cretaceous Colorado Group, is analyzed for sedimentary heterogeneity. These Cenomanian-Turonian samples are collected from West-central Alberta. The formation primarily consists of laminated calcareous mudstones with abundant fecal pellets composed of calcareous coccoliths debris representing the “white specs”. Integrating CT datasets from core and outcrop samples, 3D geometry of sedimentary bedforms existing in the 2WS Shales and Jumpingpound sandstone are determined.

For this study, outcrop samples are collected from a region south of Calgary. These are cut into slices in order to analyze bedforms in three dimensions. Oriented thin sections of mudstone, cut in three planes, will be used to determine bed microstructure and palaeoflow directions. CT data helps digitalize these slices which are further analyzed by undertaking computer modelling. This relates the geometry of cross bedding to the morphology and behaviors of bedforms.