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选择层型剖面,确定前寒武系—寒武系界线是当前国际地质学领域中的重大课题之一。目前,各国界线工作者主要运用生物地层学和沉积学方法以及一些可以利用的辅助手段对层型剖面进行研究,其目的是为查明界线地层的划分提供重要的依据和标志。然而,与上述目的一样,利用X射线粉末法对层型剖面进行系统的矿物组分分析研究的成果尚属少见。因此,笔者选择了我国南方著名的前寒武系—寒武系界线的重要地区——云南晋宁梅树村和四川峨
The selection of stratigraphic profiles to determine the Precambrian-Cambrian boundary is one of the major topics in the field of international geology. Currently, borderline workers in all countries mainly use stratigraphy and sedimentology methods as well as some available aids to study the stratotype profile, and their purpose is to provide an important basis and mark for identifying the stratigraphic division of the boundary line. However, as with the above object, the results of systematical mineral composition analysis of the stratal profile by X-ray powder method are still rare. Therefore, the author has chosen the important area of the famous Precambrian-Cambrian boundary in southern China - Meishu Village of Jinning, Yunnan and Sichuan Province