CONSTRAINING THE ONSET OF THE PALEOCENE-EOCENE THERMAL MAXIMUM IN THE HANNA BASIN, WY

The Paleocene-Eocene (P-E) Boundary is marked by a global climatic event known as the Paleocene-Eocene Thermal Maximum. It has been suggested that this period is the best known analogue for modern climate change. The Hanna Formation in Hanna Basin, Wyoming is a relatively unstudied terrestrial PETM section. Rapid uplift and subsequent erosion (during the Laramide Orogeny) led to high rates of sedimentation in the Hanna Basin. The Hanna Formation is composed dominantly of organic-rich floodplain and fine-grained alluvial fan deposits, where high sedimentation rates and the presence of fossil plant material make it an ideal place for studying the PETM. Preliminary bulk organic carbon isotope data and palynological data suggest that the onset of the PETM occurred 2700 meters from the base of the Hanna Formation. Accurately stratigraphically locating the PETM in this section allows examination of ecological changes, particularly the study of pronounced shifts in plant assemblages, across this major climate event.