赣东北石溪组的再认识

New contribution to the knowledge of the Shixi Formation in northeastern Jiangxi

从赣东北石溪组及其有关地层的沉积特征分析,弋阳北部原石溪组下段为湖泊相沉积、上段为河流相沉积,赣东北其它地区的石溪组为湖泊相沉积。依据岩性岩相特征,结合石溪组的原意及命名地石溪组的特征,弋阳北部石溪组的上界应下移至原石溪组上段的底界处。依据岩性岩相特征,结合化石组合特征及邻区相当地层的接触关系,石溪组与上覆周家店组在东乡—广丰深断裂带以北地区应属整合接触。

This paper analyses the sedimentary features of the Shixi Formation and its concerned strata in northeastern Jiangxi. The fact that the lower part of the original Shixi Formation is of lacustrine facies, its upper part is of fluvial facies in the Yiyang area and the Shixi Formation in other area is of lacustrine facies is now proved. Based on the lithological features, sedimentary facies, initial implication of the Shixi Formation and fossil assemblage, the lower part of the original Shixi Formation in the Yiyang area should belong to the Shixi Formation and the contact relation between Shixi Formation and Zhoujiadian Formation is discussed.