Wyoming's Casper Formation - Evolution of the Landscape Project

Diane Burns, Ph.D.

Project Description

The Pennsylvanian/Permian Casper Formation in southeastern Wyoming is a composed of a series of alternating limestone and sandstone beds that were formed over a 13 million year span of time. During the time that the sediments were being deposited, the environments present in the area were an offshore, shallowly-dipping carbonate platform and an onshore dune field located near tectonically active topographic highs. It is commonly believed that the source area for the sediments that comprise the sandstone units was the emerging Ancestral Rockies. Because the areas surrounding the dune field were dynamic, however, it is possible that the source area for the sandstone units may have shifted during the course of time in which the sediments in-filled the basin. Unraveling this component of the formation of the Casper sandstone units will provide a better understanding of the paleogeographic evolution of this basin. The Laramie basin is basically unproductive as far as hydrocarbons are considered, yet the surrounding contemporaneous basins are hosts to both oil and gas reserves. Why this dichotomy exists is not yet well understood.

The initial question regarding source area evolution is being investigated by Josh Dye, senior geology major at EIU, through petrologic analysis of sandstone samples collected during Summer, 2010. Results from this phase of the project will be presented at the Geological Society of America National Convention in October, 2010.

For more information about this project, please contact Diane Burns at dmburns@eiu.edu.