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杭州西湖三面环山,东接沿海平原,不仅风景秀丽驰名中外,而且其特殊的地貌形态吸引着科学工作者的注意。自从竺可桢教授指出西湖按成因类型属于“礁湖”(即泻湖)以来,已有不少文章从地貌角度论及西湖的由来,大多认为它是由海湾—泻湖演变而成。然而,能为西湖形成和演变历史提供确凿证据的,还是西湖的地层及其中所含的化石。为此,我们对西湖湖滨两个钻孔和杭州市区一个钻孔进行了微体古生物分析,结果证明:在第四纪期间,西湖经历了山间谷地—淡水湖—早泻湖—海湾—晚泻湖—淡水湖的演变过程。今日的西湖,是冰后期海面上升与河口泥沙堆积作用的产物。
Hangzhou West Lake is surrounded by mountains on three sides, and the east is along the coastal plain. Not only are the scenery beautiful at home and abroad, but also its special topography attracts the attention of scientists. Since Professor Zhu Kezhen pointed out that the West Lake is a “lagoon” by genotype, many articles have discussed the origin of the West Lake from a geomorphological point of view, and most of them consider it evolved from a gulf to a lagoon. However, it can provide conclusive evidence for the history of the formation and evolution of the West Lake, as well as the strata of West Lake and the fossils contained therein. To this end, we conducted a microbiological paleontology analysis of two boreholes in the West Lake Hubin and a borehole in Hangzhou City. The results show that during the Quaternary period, the West Lake experienced mountain valley - fresh water lake - early lagoon - bay - late Lagoon - freshwater lake evolution. The West Lake today is the product of the rising sea level and sediment deposition in estuaries in the late ice period.