The Marine OS Isotope Record of the Late Eocene And Early Oligocene

Woods Hole Oceanographic Institution, Woods Hole MA

Investigators

Abstract

Abstract The PIs propose to collect records of 1870S/1880s and more limited 8180 from DSDP sites 522 and 574 plus an on-land site in the Italian Appenines across the late Eocene- Oligocene boundary to confirm their preliminary data that show a dip and then a dramatic increase in 1870S/I 880s across the boundary. This boundary also marks the beginning of the deterioration (cooling) in global climate after the long Eocene warm period. The cause of this cooling is presently undetermined and controversial with many possible causes. This research could help narrow the causes because the Os record will be compared with 6180 record of ice volume at site 522. In addition, the on-land section will be used to compare the Os record with an independent He proxy for interplanetary dust particle (IDP) flux that is capable of lowering global ocean 1170S/I "Os. The new study will establish whether the excursion Of 1170S/1110s is a global event or not, and will help to narrow the possibilities for its cause. It will also develop the possible potential of Os isotopes as a proxy for continental weathering.