内蒙古大青山—色尔腾山地区什那干群的质疑

QUESTION ABOUT THE SHINAGAN GROUP OF THE DAQINGSHAN—SEERTENGSHAN AREA, INNER MONGOLIA

在大青山和色尔腾山地区进行地质调查时,在原来划为震旦系什那干群的地层中发现了大量确切的寒武纪化石,特别是大青山地区,在紧邻不整合面处就发现了早寒武世的三叶虫化石。因此该套地层应为下寒武统色麻沟组,而并非震旦系什那干群。同时在对色尔腾山地区震旦系什那干群进行厘定后,提出内蒙古自治区大青山和色尔腾山地区缺失震旦系沉积。这一认识将对内蒙古自治区中部的区域构造演化阶段的划分和地壳演变规律的研究具有指导意义。

A large amount of exact Cambrian fossils were found in the Shinagan Group which was classified as Sinian previously and in the immediate neighboarhood were found the Early Cambrian fossil trilobites. Thus, this suite of strata should be the Lower Cambrian Semagou Formation and not the Sinian Shinagan Group. At the same time, after the revision of the Sinian Shinagan Group of the Seertengshan area, it is proposed that the Sinian deposits are missing in the Daqingshan and Seertengshan area of the Inner Mongalia Autonomous Region. Such a recognition is of guiding significance in the division of the regional tectonic stages of the central part of the Inner Mongolia Autonomous Region the study of the evolutionary law of the Earth＇s Crust.