抄録
Basic Cenozoic geological data for the studied area in the Sakhalin Island such asroute maps showing sampling points, and columnar sections showing sampling horizons were compiled. The area studied are the Makarov and Korsakov regions of southern Sakhalin, and Shmidt Peninsula at northwestern Sakhalin. Micro-fossil biostratigraphy, geo-chemical analysis, and K-Ar dating were studied. As a result, the Oligocene/Miocene boundary, tectonic event and climatic fluctuation are discussed based on the newly established geologic age. The Cenozoic paleoenvironment related to the Pacific Ocean gateways is also discussed from the viewpoint of molluscan fauna.
