五峰期上扬子淡化海成因之探讨

A discussion on the genesis of the Wufengian desalinated sea in the Up per Yangtze Sea.

关于早古生代黑色笔石页岩的形成环境,历来存在着争论,主要是远洋成因说两种观点。但就上扬子区五峰组与龙马溪组黑色笔石页岩而论,越来越多的事实表明,它们系一套半封闭的陆表浅水滞流海盆缺氧环境下的沉积产物。

On the basis of determination of ancient salt content with C/S advanced by R.A.Berner and R.Raiswell in 1984 and through the analysis of rock specimens from the Wufeng and Longmaxi black shales, this paper presents the new views that the water in the Upper Yangtze Sea was wholly desalinated in Ashigill and early Llandovery.The factors which caused the sea water desalinated at that time are: 1.The Upper Yangtze Sea was nearly enclosed; 2.The obvious climate zones caused by the great ice cover in south pole resulted in abundant rainfall in the medium and low latitude districts.