著者

堀江 正治

出版者

Tokyo Geographical Society

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.89, no.4, pp.213-236, 1980-08-25 (Released:2010-10-13)

参考文献数

6

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Lake Biwa is the third oldest lake in the world next to Lake Baikal and C aspian and Aral Seas. Its peculiar position in the Japanese Archipelago, Deep Seated Earthquake zone, striking by negative gravity anomaly, and many endemic species of animals and plants indicate its extremely long limnetic history. In other words, if we succeed in obtaining whole sediments columns by deep boring, we can clarify many unknown facts such as glacial and interglacial features, geomagnetic events, cosmic ray variations, sedimentological phenomena, chemical composition, biological evolutions…cand so on.On the basis of this idea, the writers and their collaborators undertook deep coring operations of 200 meters at the water depth of 65 m at the center of the lake in 1971 and of 1, 000 meters at the shore in 1975-1976. This paper summarizes these results together with a discussion of our future project of extremely deep drilling in order to introduce our pioneering work of human beings.