白令海表层沉积物中的放射虫与海洋环境

RADIOLARIA FOSSILS OF THE SURFACE SEDIMENTS IN THE BERING SEA AND ITS SEDIMENTARY ENVIRONMENT

通过对白令海 1 2个表层沉积物中微体生物化石放射虫的分析 ,共鉴别放射虫 2 4 72枚 ,计36属、45种。表层沉积物中放射虫的分布特点为 :1 .浅水陆架 -陆坡上部区的粉砂、细砂沉积物中放射虫化石数量少且属种单调。2 .陆坡下部区的火山碎屑及浊流沉积物中放射虫化石亦不丰富。3.海盆区粘土沉积物中的放射虫化石丰度高且分异度高。本区陆架放射虫化石的优势种为Spongotrochus glacialis.影响放射虫分布的主要因素为海流、地形、水深、水温等。另外 ,该区沉积物的物源主要为陆源沉积物、生物源沉积物和火山源沉积物 ,它们主要来源于俄罗斯东部的勘察加半岛。

Total number 2472, 36 genera and 45 species are distinguished after the radiolaria fossils from 12 surface sediments in the Bering Sea are analysed. The distribution characteristics of radiolaria fossils in the surface sediments is as follows: 1. From the shelf of shallow water to the upper area of continental slope, there are a few radiolaria fossils and monotonous genus and species. 2. In the low area of continental slope, radiolaria fossils are poor in the volcanic cinders and turbidite. 3. The abundance and diversity of radiolaria fossils are high in the clay of basin. The dominant species of radiolaria is Spongotrochus glacialis on the continental shelf. The current, topography, water depth, water temperature etc. are key factors influencing radiolaria distribution. The sources of sediments mainly are terrigenous sediments,biogenic sediments and volcanic sediments in the suvey area and they are mostly from the Kamchatka Peninsula in the east of USSR and Aleutian Islands.