扬子区震旦纪海平面波动与控矿作用

SINIAN SEA LEVEL FLUCTUATIONS AND ORE-CONTROLLING PROCESSES IN THE YANGTZE AREA

摘要:

震旦纪是扬子区的重要成矿期,这一时期形成了一系列沉积矿床,如贵州的大塘坡锰矿、湖南民乐锰矿、江口锰矿、湘潭锰矿和贵州开阳磷矿、湘西磷矿、保康磷矿、荆襄磷矿等。对于这些矿床的成因已有不少学者进行过论述,但各家观点不尽一致。这些矿床基本上都分布在贝义西(长安)冰期的冰碛岩和南沱期冰碛岩之上。本文以此为基点展开对震旦纪沉积矿产的控矿、成矿因素的探讨。

Abstract:

On the basis of the distribution of the Sinian manganese, phosphorite and iron deposits in the lower part of the transgressive sequences on the Chang' anian and Nantuoian tillite horizons, the sea level fluctuations created by glaciation are believed to be the main controls on the formation and distribution of the Sinian phosphorite, manganese and iron deposits, and thus the mineralization models of the Sinian phosphorite and manganese deposits in the Yangtze area are proposed. In addition, the characteristics of δ ¹³C and δ ³⁴S, rare earth elements and trace elements from the Sinian manganeseand phosphorite-bearing series are similar to the diagenetic and mineralization, characteristics caused by the Cenomanian—Turonian （Cretaceous） sea level rises in Europe. This demonstrates the correctness of the theory of "upwelling current" caused by the Sinian post-glacial sea level rises.