This project will construct whole-Cenozoic record of eolian deposition from ODP Leg 121 drillsites in the eastern Indian Ocean. That record will reveal the history, on tectonic timescales, of Southern Hemisphere atmospheric circulation intensity and of patterns of continental (largely Australian) aridity. Further the data will link the entire late Cretaceous to recent eolian record to the history of the ocean and cryosphere based on isotopic and other proxy indicators determined from the same core, and sometimes the same samples. There are several specific questions or events to be investigated. The first of these is the nature of any changes in atmospheric circulation across the Cretaceous-Tertiary boundary. Secondly, to delineate the Southern Hemisphere record of the important change in atmospheric circulation that occurs in the Northern Hemisphere at the Paleocene-Eocene boundary. Third, examine significant changes in Southern Hemisphere atmospheric circulation that occur in conjunction with the latest Eocene - early Oligocene polar cooling and changes in Antarctic ice volume. In this regard the fact that wind intensity is another indication of the planetary temperature gradient means that the data will place further constraints on the ice-volume vs. temperature discussions. %%% The effects of paleoclimatic changes during the last 60 million years on atmospheric circulation may be determined from changing patterns of wind-blown particles in deep-sea sediments. This project will utilize the eolian material in drill cores from the Indian Ocean to infer shifting wind patterns that may be linked to climate changes. Because the atmosphere is very sensitive to climate, these paleocirculation results will provide a monitor of paleoclimatic changes in the Southern Hemisphere. This information will be very important in modelling studies of the Indian Ocean response to Antarctic glaciation, uplift of the Tibetan Plateau, and the effect of the Northern hemisphere glaciation.
