Texas A&M University, United States

The "Paleocene/Eocene Thermal Maximum" or PETM was associated with dramatic warming of the oceans and atmosphere, pronounced changes in ocean circulation and chemistry, and upheaval of the global carbon cycle. Many relatively complete PETM sequences have by now been reported from around the world, but most are from ancient low-to midlatitude sites. ODP Leg 189 in the Tasman Sea recovered sediments from this critical phase in Earth history at Sites 1171 and 1172, potentially representing the southernmost PETM successions ever encountered. Downhole and core logging data, in combination with dinoflagellate cyst biostratigraphy, magnetostratigraphy, and stable isotope geochemistry indicate that the sequences at both sites were deposited in a high accumulation rate, organic rich, marginal marine setting. Furthermore, Site 1172 indeed contains a fairly complete P-E transition, whereas at Site 1171, only the lowermost Eocene is recovered. However, at Site 1172, the typical PETM-indicative acme of the dinocyst Apectodinium was not recorded. (modif. j. abstr.)