Report on activities of the WG on North Pacific Paleogene in 2003-2004:

1. A field work was organizied to enable Russian and Japanese geologists (paleontologists and lithologists) to examine the key Paleogene sections of northeastern Kamchatka and North Japan (Hokkaido). The sections were sampled for microfaunal (foraminifers and diatoms) analyses. The samples are under study now. Macrofaunal samples (mollusks) have been also collected. A comparative study of the Paleogene sections of different climatic belts may form a base for reliable correlation of these sections and subtropical and tropical biotic assemblages of the North Pacific.

2. Special investigations have been initiated to study Oligocene deposits of the North Pacific surrounding structures. The studies include thorough analysis of sections from Japan (in the south) to Chukotka (in the north) and from Alaska (in the north) to California (in the south). About 15 specialists are involved. Comprehansive investigations have been carried out in two Oligocene sections of West Kamchatka, where some horizons, zones and beds were outlined for the first time and a new model for their correlation to other North Pacific sections was worked out. Special significance is attatched to monographic description of Oligocene marine fauna and flora to be completed in the next years. By the present, more than 100 molluscan species, about 20 species of leaf flora, and over 35 species of foraminifers have been described.

A series of paleobiogeographic maps are planned to be compiled in the next years to show areas of distribution and migrations of the North Pacific biotic assemblages during the Oligocene time. The Oligocene stratigraphy of the region will be consiodered in several articles and a special monograph.

Report by Yu. I. Gladenkov, Chairman.