震旦系有关问题的讨论

“震旦系”是我国最早提出并普遍使用的一个时间地层单位。1922年葛利普在其论“震旦系”的文章里^1],大致规定它的含义是:“在寒武系之下,变质的更老岩系(五台或泰山岩系)之上的未变质或浅变质的沉积层”。1924年,李四光记述了长江峡东区不整合覆于变质的三斗坪群之上,整合伏于寒武纪含三叶虫化石的石碑页岩之下的一套不变质地层,并援引葛利普定义而命名为震旦系。

DISCUSSION ABOUT SOME PROBLEMS OF THE SINIAN SYSTEM

This paper is a reply to the article "A question on the Sinian System and related prolems of Upper proterozoic Erathem in China" by Prof.Chao Tsungpu.In Chao’s paper he has asked a series of questions about the foundation,classification and correlation of the Sinian System,and consequnently he attempts to abolish the Sinian System in place of founding a new unit termed the "Sinian Group".The present authors uphold that the Sinian System,an only chronostratigraphic unit first named in China,is correct in the aspect of foundation as well as the principles of classification and correlation.In addition,it is stratigraphically characterized by stable position and continuous succession.The term Sinian System possesses the priority of nomenclature,and has been attached importance to and met with acceptance by many geologists.So that,it should not be allowed to be abolished rashly.The term "Sinian Group",however,is riddled with errors in a matter of principle and it was named much later than others.So if it is recommended to the international geological circle as a chronostratigraphie unit,(it should be making,)a,serious mistake and confusion would arise thereby.As for "Xiadong System",if it is receivable,it would be only a local lithostratigraphie unit but not a chronostratigraphic one.It "will be certainly incapable of replacing the Sinian System.In sum,arguments raised by Prof.Chao in the above mentioned article definitely need further discussion and consideration.And some of them in that article are ill proved or proofless.The Sinian System on its basic principles is beyond all question.We must seek truth from facts,and make efforts to eliminate differences appearing in practical utilization of the Sinian System to make it to be a scientific and perfect chronostratigraphic unit of the uppermost Precambrian.