摘要
我们在北京地震地质会战工作所获实际资料的基础上,曾对北京平原区上新统一更新统的划分提出了初步看法,将第四系下限定在顺义组和夏垫组之间,年龄为距今243万年。
Abstract
In 1979,we suggested that pliocene-pleistocene boundary in Beijing plain,based on the results of seismological and geological research,may be placed between the Pliocene Shunyi Formation and the Pleistocene Xiadian Formation, deter about 2.43 m.y.B.P. Since then, we have studied more cores, measured their CaCO content and thermolumlnescene; Micratektltes from the Zhnili Formation,insecte fossils of Diptera from the Xiadan Formation of well No,l in Shunyi have also been discovered. These are sound evidurces for the subdivision of Quaternary and the determination of its lower boundary in this area.
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