Abstract: Stratigraphic Evolution of Sakhalin Island, Russia: Relationship to Neogene Siliceous Deposition in the North Pacific

Joyce R. Blueford, Lisa D. White, Yuri Gladenkov

Sakhalin Island is an extension of the Japanese archipelago and has a similar geological history. Five Neogene basins were created during three episodes of lateral compression: the late Oligocene to early Miocene; middle to late Miocene; and late Pliocene to Pleistocene.

The North Sakhalin Basin is the largest of the five basins and composed mainly of Miocene-Pliocene deltaic sediments of the paleo-Amur River. Lower Miocene diatomaeous shales underlie deltaic sandstones. This basin is not fully explored and new data suggest extending the basins toward the northwest. The East Sakhalin Basin originally included part of the North Sakhalin Basin. Miocene sedimentary rocks generally overlie Cretaceous volcanic rocks, but in some areas Oligocene sedimentary rocks overlie the Cretaceous volcanics. East Sakhalin Basin includes Oligocene through Pleistocene sediments of the deltaic, littoral, and nearshore neritic deposits of the paleo-Amur Delta. The Terpeniya Gulf Basin and its onshore extensions are bounded on the west by the Central Sakhalin thrust zone. Sequences of siltstones, sandstones, diatomites, and mudstones are present. The Aniva Gulf Basin is bounded on the west by the Central Sakhalin thrust zone. Miocene sandstones, diatomites, and siltstones are the main deposits. The Tatar Strait Basin extends south towards the western part of Hokkaido, but does not extend into the Russian mainland. This basin evolved in the Late Cretaceous and overlies older eugeosynclinal rocks. Eocene deep sea sediments are found in this basin.

Neogene siliceous rocks of these basins are compared with other Neogene deposits in the northern Pacific. Radiolarians, diatoms, mollusks, and foraminiferas reflect a boreal paleoenvironment.

AAPG Search and Discovery Article #90958©1995 AAPG Pacific Section Meeting, San Francisco, California