Petrographic and Geochemical Analysis of the “Chattanooga” (Late Devonian Early Mississippian) Black Shales in the Southern Midcontinent.
Oklahoma State University Stillwater Oklahoma
While gas shales are important economically, there are still many gaps in our understanding of the processes that generate source beds and reservoirs in mudrocks. This project will assist in the development of emerging gas shale plays by applying an interdisiciplinary approach that combines petrographic, geochemical, and stratigraphic analyses specifically to the characterization of the “Chattanooga” (late Devonian and early Mississippian) black shales. “Chattanooga black shales” are major producers of hydrocarbons, and are exposed in several locations in northeastern Oklahoma, southwestern Missouri, and western Arkansas. While the name “Chattanooga” is used to describe black shales in all of these areas, none of these rocks can be directly correlated to the type locality. Thus, while they may be time-correlative, it is likely that they were deposited in different environments ranging in both water depth and proximity to shore. Outcrop-based lithologic descriptions will be combined with gamma-ray spectrometry, organic carbon and trace metal-concentrations and x-ray diffractometry to delineate different facies. Ultimately, this study will yield a refined conceptual model that will aid in the reconstruction of the depositional history of these important gas-bearing reservoirs.
AAPG Search and Discovery Article #90094 © 2009 AAPG Foundation Grants in Aid