Comparative Hydrologic Changes in the Mid-Atlantic Coastal Plain during the Eocene Thermal Maximum 2

The Eocene was punctuated by a series of rapid warming events that are referred to as hyperthermals. The oldest was the Paleocene-Eocene Thermal Maximum (PETM), which is considered to be one of the closest approximations in the geologic record to modern-day anthropogenic warming. Considerably less attention has been paid to later hyperthermal events, including the Eocene Thermal Maximum 2 (ETM2), which is the second hyperthermal event (c. 53.7 mya) both in order and magnitude. The motivation for studying the ETM2 is that it allows us to 1) observe how the earth system responded to varying levels of carbon release and 2) attempt to separate what observations can be attributed to carbon forcing and what are a result of background variability. This study utilizes a newly discovered section within the Knapps Narrows core from Maryland in the Mid-Atlantic Coastal Plain of the United States wherein we have identified the ETM2 by means of benthic foraminiferal carbon isotopes, calcareous nannofossil biostratigraphy, bulk carbon isotopes, and magnetostratigraphy. Measurements were made of changes to clay mineralogy and dinoflagellate assemblages to determine if hydrologic changes during ETM2 were comparable to those observed during the PETM along the Atlantic Coast. Preliminary results show a shift in clay mineralogy similar to changes observed during the PETM, suggesting that similar hydrologic changes occurred during both hyperthermal events. As a result, renewed questions on the authigenic nature of changes in mineralogy during the PETM are raised.