Oji International Seminar for IGCP-246 ; sponsored by the Japan Society for the Promotion of Science and the Fujiwara Foundation of Science ; supported by Geological Society of Japan, Palaeontological Society of Japan and Shizuoka University ; IGCP-246 "Pacific Neogene Events in Time and Space" (PANETS) project leader, R. TsuchiShizuoka University[1988]