Appearance process of the Cenozoic cold-water molluscan assemblages in the Japanese Islands

日本列岛新生代冷水软体动物组合的出现过程

基本信息

批准号：
02640606
负责人：
OGASAWARA Kenshiro
金额：
$ 1.34万
依托单位：
The University of Tsukuba (1991-1992)Tohoku University (1990)
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1992
项目状态：
已结题

项目摘要

The purpose of this research is to make clear the appearance process of Cenozoic cold-water fauna in the Japanese Islands on the basis of shallow-marine molluscan records. Firstly, the definition of the cold-water realm from zoogeographic point of view has been studied based on modern marine zoogeographic studies in relation to various data of surface temperature. As the result, the relationship between the zoogeographic divisions and annual mean temperature of Northern Pacific can be divided into the Subarctic (less than 8ﾟC), Cool-temperate (14-9ﾟC), Mild-temperate (16-15ﾟC), Warm-temperate (20-18ﾟC) and so on, respectively. Secondly, comparative analysis and interpretations from paleomarine-climatical viewpoint on the Japanese Cenozoic molluscan assemblages have been done based on modern analogous method as referring the characteristic molluscan genera/species of the arctic/subarctic realms. Consequently, it can be concluded that l) the Oyashio-type cold-water mass has not been appeared in Northern Pacific during the Miocene, 2) shallow marine cold-water molluscs have first appeared at latest Plioecne to early Pleistocene time at southern Hokkaido, that are of the cool-temperate origin, and 3) Sea of Japan and Sea of Okhotsk might be addorded the important biotope (biotic places) for such adaptation as from the cool-temperate to subarctic marine conditions corresponding world-wide cooling event towards the Glacial age (Quaternary).

本研究的目的是根据浅海软体动物记录来明确日本列岛新生代冷水动物群的出现过程。首先，从动物地理学的角度研究了冷水域的定义。根据现代海洋动物地理研究的各种表面温度数据，北太平洋的动物地理分区与年平均气温的关系可分为亚北极（小于北极）。 8°C）、冷温带（14-9°C）、温温带（16-15°C）、暖温带（20-18°C）等。其次，分别进行比较分析和解释。参照现代类比方法，参考特征性软体动物，对日本新生代软体动物组合进行了古海洋气候观点的研究。通过对北极/亚北极地区的属/种进行考察，可以得出以下结论：l) 中新世北太平洋尚未出现亲潮型冷水团；2) 浅海冷水软体动物首先出现于北海道南部的上新世至更新世早期，属于冷温带起源，3）日本海和鄂霍次克海可能会增加重要的影响。群落生境（生物场所），用于适应从冷温带到亚北极海洋条件的全球变冷事件，直至相应的冰川时代（第四纪）。