Date of Award


Document Type


Degree Name

Master of Science (MS)



First Advisor

R.D. LeFever


The Birdbear Formation of the Williston Basin of southwestern North Dakota represents one carbonate-evaporite sequence of the Late Devonian. The formation was deposited during regression on a broad, shallow epeiric shelf and is composed principally of dolomite, limestone and anhydrite. The Birdbear Formation is conformable with the Duperow Formation below and the Three Forks Formation above. The designations of 17 lithofacies form the context for describing hydrocarbon generation, migration and accumulation. Rock-Eval 6 and total organic carbon of 42 samples were used to identify the quality of source rocks present in the formation. Good and excellent source rocks were identified in both the upper and lower members, at varying intervals, as organic rich limestones, microbialites and stromatolites. The vertical terminus of each interval is anhydrite, forming excellent seals to the present source rocks and providing conduits to three stratigraphic traps. The Birdbear Formation of the Williston Basin in southwestern North Dakota encapsulates the vital components for a complete petroleum system.

Included in

Geology Commons