CENOZOIC PALEOGEOGRAPHY AND CLIMATE-CHANGE IN THE NORTH PACIFIC-OCEAN

The transitional zone from the Pacific Ocean to the Northeastern Asia continent provides a unique region to study the Cenozoic geological pr ocesses in the boreal climatic belt. This region belongs to the Asiati c convergent margin where thick sedimentary deposits occur. New Paleog ene and Neogene stratigraphic schemes for the Kamchatka Peninsula and surrounding areas, including nearly 15 horizons, a number of zones and ''beds with fauna'', form the basis for this summary of geological ev ents. The paper deals mainly with molluscan faunas. Paleobiotic evolut ion on the continental shelf, as well as paleogeographic and paleoclim atic changes were studied and six major periods of warmth ''climatic o ptima'' were recognized. Many of these environmental changes reflect g lobal climatic events. The stratigraphic scheme of the Kamchatka Penin sula is discussed with reference to that of North America.