Abstract: Tectonic Evolution and Sedimentary Basins of the Eastern Regions of Russia

Natalia V. Bocharova, Jan Golonka, Kris E. Meisling

The mosaic of eastern Russia terranes assembled due to interaction of the Eurasian, North American, Chukotka, Pacific, Kula plates, and several microplates in Mesozoic and Cenozoic. Plate interactions produced a variety of depositional environments in sedimentary basins including foredeeps, forearc depositional platforms, back-arc basins, rift systems, marginal basins, and intermontane depressions.

The Early Cretaceous convergence of the Eurasian and Chukotka plates was accompanied by opening of the Canadian Basin and subduction of the Anui-Anvil Ocean. Collision of the Chukotka and Omolon blocks with Eurasia resulted in the Chersky terrane deformation, and complex tectonic structure of the Kolymian Loop. The Zyryanka Basin formed on the trapped oceanic crust was later developed as an intramontane depression. The subduction of the Kula plate under Eurasia produced the Okhotsk-Chukotka volcanic belt and Anadyr-Koryak accretionary terrane.

The Cenozoic accretionary evolution of Eurasia produced successively oceanward-stepping volcanic arcs: Paleocene-Lower Eocene Anadyr-Bristol, Middle-Upper Eocene Koryak-West Kamchatka, Oligocene Central Kamchatka, Miocene East Kamchatka-Kurile. The Magadan, West Kamchatka, Central Kamchatka, and East Kamchatka basins developed as forearc depositional platforms.

The Okhotsk Sea block and Olutor arc collided with Eurasia in the Middle-Late Eocene. The plate adjustment produced Oligocene-Early Miocene subduction under East Sakhalin, extension in the Kashevarov and St. Iona troughs, back-arc extension in the Strait of Tatar, and thick sedimentary prism of East Sakhalin Basin. The Deryugin Basin is interpreted as a marginal depression of the Okhotsk microcontinent. The Tinro, South Kurile and Shelikhov basins were produced by back-arc spreading.

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