中国震旦系、青白口系新见

<正> 青白口系在天津蓟县出露,下与蓟县系呈不整合接触,上与寒武系下统府君山组呈平行不整合接触,与震旦系没有直接接触关系。震旦系在峡东地区出露,下与黄陵花岗岩呈沉积不整合接触,与青白口系没有直接接触关系。也就是说震旦系与青白口系的关系没有衔接剖面控制,因而将震旦系叠置于青白口系之上是缺少衔接剖面基本的地质依据。笔者认为辽南及苏皖北部晚前寒武纪地层层序可以解决二者的关系。由于人们对辽南及苏

A new point of view concerning Sinian and Qingbaikou Series of China

Qingbaikou Series occurs in Jixian, Tianjin, where it is overlain unconformably by Fujunshan formation of the Lower Cambrian Series and has no direct relation with the Sinian Series.Sinian Series occurs in eastern Yangzi Gorge of Hubei province, where it overlies unconformably the Huangling granite and has no direct relation with Qingbaikou Series.Owing to lack of directly contacted profile section, the formerly proposed stratigraphic time scale, in which the Sinian Series is placed above the Qingbaikou Series, has not enough geological basis.There is a widespread regional unconformity between Sinian and Qingbaikou Series.At this un-conformable boundary the biological evolution shows mutation appearing, for the first time, mollusk ver-mcs and skeletal animals (sponge).Furthermore the strata below and above the unconformity show very different fold-type.Thus, this boundary has epoch-making significance, and the Sinian Series above this boundary may therefore be classified to paleozoic system, the isotopic age of its lower limit is 700±20 Ma.and its upper limit is 600±10 Ma.The Sinian Series is the first overlying sedimentary strata of Chinese Platform.The Qingbaikou Series and its equivalent strata belong to upper Protero-zoic System.