Sedimentary Processes Linked to Toc Content of Shallow-Marine Shales – Cretaceous Interior Seaway, Northern Colorado
Geosciences, Colorado State University, Fort Collins, CO, USA
Shales are increasingly important as unconventional reservoirs, yet their formation processes are still only partly understood. In contrast to most current studies that focus on shales from the deep shelf this project will focus on deposition and its link to the Total Organic Carbon (TOC) content of the resulting sedimentary rock.
Based on previous work from the deep shelf, this project will investigate how much suspension versus bed-load transport occurs in different positions on an offshore transect represented by the Lower Cretaceous Skull Creek Formation that is outcropping in northern Colorado. Distinguishing suspension-derived sediments from bed-load deposits would not only clarify depositional processes and their variations in the offshore realm but also define which type of facies preserves how much TOC, and therewith link sedimentological processes to the organic content of the rock. This approach, here applied to one specific Cretaceous succession, is most likely applicable to all other siliciclastic offshore successions, and the methods developed for this research can be transferred to other offshore petroleum-bearing succession worldwide.
This research will be undertaken by combining detailed outcrop, petrographic/microscale and geochemical work on well-exposed successions along the Front Range, Colorado, that have a continuation into the subsurface of the Denver-Julesberg basin. Despite an increase in understanding of depositional processes in the offshore environment, this study will link basic sedimentological processes with applied research as the Skull Creek Formation is not only a source rock for the Cretaceous succession in the basin, but also a potential unconventional reservoir.
AAPG Search and Discovery Article #90199 © 2014 AAPG Foundation 2014 Grants-in-Aid Projects