Radiolaria fossils in the surface sediments and sedimentary rnenvironment in the Bering Sea

摘要

Totally 2472 grains of Radiolaria belonging to 36 Genera and 45 species are rndistinguished from 12 surface sediments in the Bering Sea. The distribution rncharacteristics of Radiolaria fossils in the surface sediments are as follows: (1) From rnthe shelf of shallow water to the upper of continental slope, there are a few Radiolaria rnfossils and monotonous genus and species; (2) In the lower of continental slope,rnRadiolaria fossils are poor in the volcanic cinders and turbidite; (3) The abundance and rndiversity of Radiolaria fossils are high in clay of the basin. The dominant species of rnRadiolaria is Spongotrochus glacialis on the continental shelf. Current, topography,rnwater depth, and temperature etc. are key factors influencing Radiolaria distribution.rnThe sources of sediments mainly are terrigenous, biogenic and volcanic sediments in the rnsurvey area and they are mostly from the Kamchatka peninsula in the east of Russia and rnthe Aleutian Islands.