PALEOGEOGRAPHY AND PALEOCURRENTS OF THE BARREMIAN STRATA IN JAPAN, NE CHINA AND SIKHOTE-ALIN (RUSSIA)
Abstract Barremian strata are exposed in Japan, NE China and Sikhote-Alin, and consist of nonmarine and marine sediments that yield fossil molluscs, conchostracans, dinosaurs and terrestrial plants. Because of the interfingering relationship between nonmarine and marine sediments, the coast of the eastern margin of the Asian continent in Barremian time is identified with in these areas. These areas were strongly influenced by sea-level change, the second transgression phase as recognized around Japan. The Tetori Group and the Severosuchanskaia Formation in southern Sikhote-Alin are interpreted to have been deposited under a same Barremian gulf whose north-facing mouth, as interpreted by paleocurrent directions, facies relationships, and the occurrence of common nonmarine bivalve species. The occurrence of ammonites and inoceramids, found in the Tethys, NW Europe, northern Pacific and Boreal provinces, in southwest Japan, NE China and Sikhote-Alin, provides important evidence for both cold and warm currents originating in the Arctic and near the Equator, respectively. Both current distributions in southwest Japan, NE China and Sikhote-Alin during the Barremian are inferred from the coriolis force. The gulf is identified from the Tetori Group and the Severosuchanskaia Formation and is considered, therefore, to be influenced by the current from the Arctic.