Geologic Structure Map

During Paleozoic time, thick accumulations of limestone and dolostone with lesser thicknesses of
sandstones, siltsones, shales, and evaporites were deposited in eastern Montana and Wyoming. Several large structural features were formed during Latest Cretaceous to Paleocene time when tectonic activity associated with the Laramide Orogeny rejuvenated basement structures in the region. Several of these structural features are now productive oil and gas traps and form the domes in the map below. Deep sediment layers are found within the highlighted basins with saline aquifers with potential for carbon storage.