Date of Award


Degree Name

Master of Arts



First Advisor

Dr. Robert Anemone

Second Advisor

Dr. Kathleen Baker

Third Advisor

Dr. Jaqueline Eng

Access Setting

Masters Thesis-Campus Only


Recent geological and paleontological investigations into the Freighter Gap region of the Great Divide Basin in southwestern Wyoming has allowed the definitive correlation of this area to the geological and biostratigraphical frameworks developed for late Paleocene through middle Eocene times in North America. This study has been able to identify the Scheggs Bed of the Tipton Tongue of the Green River Formation in the Freighter Gap region. The Scheggs Bed is a widely used unit of correlation throughout the Greater Green River Basin, and the isochronous nature of the boundaries of this unit allows an accurate temporal framework to be added to the Freighter Gap region.

Sediments in the Freighter Gap region were deposited between -53 and 50Ma, spanning the entire time of the Early Eocene Climatic Optimum (52-50Ma). Fossils from the area are Wa6 and Wa7 in age, the boundary of which lies unresolved in a 62 meter section. However, paleomagnetic surveys in the Freighter Gap region would be able to quickly and accurately narrow this margin dramatically, as the Wa6/Wa7 boundary also corresponds in time to the onset of magnetic chron C24n.ln.

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