The geological evolution of the Indian Ocean is the most poorly understood of all the major ocean basins. In part this has resulted form diversity of approaches and objectives of the major research cruises in the Indian Ocean. Both United States and foreign scientists have concentrated on specific tectonic or sedimentary problems, but no major cruises have concentrated on an integrated understanding of its geologic history. This has resulted in a wide distributed and non-uniform data base. A second problem has been the logistical complexity of supporting U.S. and foreign cruises in the Indian Ocean, resulting in an overall data base in any country that is insufficient to adequately address the total history of the ocean basin. The objective of the present recommended award is to compile topographic, magnetic and satellite derived gravity field from the Indian Ocean. U.S. scientists will work closely with French and Australian researchers to ensure that the data base includes results from the most recent cruises. These compilations will be used to define (1) the early opening history of the Indian Ocean; (2) the separation of Australia and Antarctica; and (3) the closing of the seaway between Indonesia and Australia. Paleodepth charts will aid in determining the sedimentary history of the basins in the Indian Ocean. The overall compilation will be important in integrating existing data with the results of drilling planned by the Ocean Drilling Program. This is a coordinated study involving scientists from U.S. and foreign institutions. Dr. John Sclater of the University of Texas has responsibility for overall coordination of the project. He will be working with Drs. Robert Fisher (Scripps Institution) and Dr. Steven Cande (Lamont-Doherty). Drs. Roland Sclich (France), Michael Coffin (Australia) and Hugh Bergh (South Africa) will provide foreign data. The principal investigators are highly qualified and funding is strongly recommended at the following levels: FY87 & 88 FY89 & 90 Texas 69,785 73,731 Scripps 59,547 77,665 Lamont 75,654 73,141
