晚更新世冰期最盛时长江中下游地区的古环境

本世纪七十年代初,关于“新的冰期何时来临”的一次国际性学术讨论会,曾惊动过国际新闻界与一些国家的政府部门,为此人们很想了解“冰期时代”的地球环境究竟是什么样子? 自七十年代后期至今,国内外出现了一系列论述距今18000年前后末次冰期盛时地球环境特征的论著。

THE PALEOENVIRONMENT OF THE MID-LOWER REGIONSOF CHANGJIANG IN THE FULL-GLACIAL PERIODOF LATE PLEISTOCENE

In this paper the author, based on the analyses of the sedimental features and the paleonto-logic informations in the Mid-lower regions of Changjiang at 18000 yr. B.P., concludes that the temperature was lower at that time than at present and the precipitation was less by then. The wind force was so strong that the loess accumulated on the plains or the hilly regions and the dunes which consist of the older river sand were formed near the lake rims or the bank sides. At the same time, the headward erosion took place along the Changjiang Valley due to the drop of the world sea-level in the full-glacial period. The paleochannel bottom had reached a depth about - 60 m at the north of the present debouch and the water level of main stream in the Mid-lower Changjiang Valley was about 20 - 45 m lower than present, thus provided the Dongting, Poyang and Taihu lakes regions with different erosional plain.