The Bighorn Basin Coring Project will collect ~200 meters of core from each of three sites (Polecat Bench, Gilmore Hill, Basin Substation) in the Bighorn Basin of Wyoming to better constrain the causes and effects of Paleogene hyperthermal events. Hyperthermals are abrupt, large-magnitude global warming events associated with extreme perturbations to the Earth's carbon cycle. Two events in particular will be targeted - the Paleocene-Eocene Thermal Maximum (PETM, ETM1) and the Elmo (ETM2) event. The PETM is the best documented hyperthermal and involved the release of 2,000-6,800 gigatons (Gt) of carbon from an unknown reservoir over less than 10 thousand years (ky) causing the earth to warm by 5-9ºC for a period of 100-200 ky. For comparison, the entire fossil fuel resource base on earth today is estimated to be ~5,000 Gt. Elmo is a smaller amplitude event that occurs after the PETM and just below the Chron C24N/C24R polarity reversal in marine records but remains poorly documented in continental sections. By applying a variety of sedimentological, geochemical, and palynological methods to the proposed cores we hope to better understand what caused these events, study the biogeochemical and ecological feedbacks that operated during them, and reveal precisely how they impacted continental environments. The Bighorn Basin preserves the most expanded stratigraphic records of the PETM and Elmo yet known, so these cores will provide an opportunity to study hyperthermals at unprecedented resolution.
