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    华北晚前寒武纪(中、新元古代)岩石地层单位及多重划分对比

    Late Precambrian (Meso-to Neoproterozoic) lithostratigraphic Units in North China and their multiple division and correlation

    • 摘要: 提要:晚前寒武纪地层是华北早前寒武纪褶皱变质基底之上的第一套沉积盖层。主要发育和分布于华北晚前寒武纪的一些裂谷系—裂陷槽中,但各地沉积开始时间早晚不一,后期遭受剥蚀程度不一。长期以来在地层划分、岩石地层命名、使用及年代属性上认识不统一,在一些地区认识分歧很大。笔者在岩石地层单位、地质特征认识的基础上,进行了全区(群、组)统一对比,明确了可作为华北晚前寒武纪沉积序列的代表性岩石地层单位及岩石组合特征;并介绍晚前寒武纪叠层石组合、微古植物特征性分子和已发现的宏观藻类和后生动物,论述了层型所在地区年代地层划分及层型以外各地层分区岩石地层单位年代属性的确定依据。

       

      Abstract: Abstract: Late Precambrian strata are the first sedimentary cover on the early Precambrian folded metamorphic basement in North China. They are mainly distributed in some late Precambrian rift systems and aulacogens in North China, but the timing of deposition varies from area to area and the strata underwent more or less erosion in the late stage. Diverse views have long existed about the stratigraphic division and naming, use and age assignment of lithostratigraphic units. The divergence is even great in some areas. On the basis of the understanding of the geological characteristics of lithostratigraphic units, the author makes the stratigraphic correlation throughout the region and put forward unifying groups and formations, determines the features of representative lithostratigraphic units and rock associations that may serve as late Precambrian depositional sequences in North China, introduces the late Precambrian stromatolite assemblage and characteristic elements of the microflora, as well as mega-algae and metaphytes, and discusses the evidence for determining the chronostratigraphic division in the area where the stratotype is located and the age assignment of the chronostratigraphic units in various stratigraphic areas beyond the area of ??the stratotype.

       

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