Geohistorical succession of the Japanese Cenozoic shallow-water benthic faunas and their relation to the Late Shallow-Tethys fauna

日本新生代浅水底栖动物群的地史演替及其与晚浅特提斯动物群的关系

基本信息

批准号：
62540593
负责人：
OGASAWARA Kenshiro
金额：
$ 0.83万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1988
项目状态：
已结题

项目摘要

The Japanese Cenozoic shallow-water faunas have been considered to a representative of the Indo-West Pacific element which was originated in the shallow Tethys regions. However, recent studies suggested that there are some East-Pacific element in the Japanese Cenozoic. The present study is a trial to consider the geohistorical proccess of birth of the Japanese Cenozoic shallow-water faunas from a zoogeographic oint of view. The following outlines are summerized mainly based on comparative studies on shallow-water elements between the Japanese and Tethys regions;1. Related genera and species between the two regions are recognizable during the Mesozoic2. There are some elements in common between the two at the Paleogene although data is insufficient3. At the early Middle Miocene, there are some common warm-water elements in the area from Java, Philippines through Southwest Japan to southern Hokkaido4. After the early Middle Miocene, there is no element in common between the two5. At the early Middle Miocene, there are some. characteristic elements restricted in the Taiwan-Yaeyama regionThese tentative conclusions from paleozoogeographic point of view are examined from the paleogeographic, paleoceanographic and paleoclimatic studies. Consequently, it can be said that the proto-Kuroshio Current first appeared at the early Miocene corresponding to form a zoogeographic barrier between the Indian and Westerm Pacific oceans. Such paleogeographic and paleoceanographic backgrounds maight be permitted a wide invasion of Miocene warm-water elements to the North, Succeed this event, faunal endemism of the Late Miocene Japanese shallow-water fauna maight be progressed corresponding to cooling event of about 5 ゜C mean temparature decrease which is estimated by paleobotanical studies.

日本新生代浅水动物群被认为是起源于特提斯浅海地区的印度-西太平洋成分的代表，但最近的研究表明日本新生代也存在一些东太平洋成分。是从动物地理学的角度思考日本新生代浅水动物群诞生的地史过程的尝试，主要基于浅水要素的比较研究，总结出以下概要。日本与特提斯之间的关系；1.在中生代，两个地区之间存在一些共同点，尽管数据不足。 -中中新世早期之后，从菲律宾爪哇到日本西南部到北海道南部地区的水元素，两者之间没有共同点5。台湾-八重山地区从古地理、古海洋学和古气候研究的角度，从古动物学的角度得出了这些初步结论，可以说，原黑潮最早出现在中新世早期，对应于印度与印度之间形成了动物地理屏障。这种古地理和古海洋背景可能允许中新世暖水元素向北方的广泛入侵，成功。在这一事件中，晚中新世日本浅水动物群的动物特有性可能会随着古植物学研究估计的平均气温下降约 5 ゜C 的降温事件而得到进展。