皖西凤台组重力流及滑塌沉积

GRAVITY FLOW AND SLUMP DEPOSITS OF THE FENGTAI FORMATION IN WESTERN ANHUI

分布于皖西淮南、霍丘一带的震旦系上统凤台组,是一套以杂砾岩为主的碎屑岩系,其中富含碳酸盐岩成份。在区域上,它与豫西罗圈组层位大致相当。对凤台组杂砾岩的成因,长期存在着几种不同认识,但大多数研究者认为是冰川形成的底碛和冰湖沉积。根据作者对该组杂砾岩的沉积构造、岩石学及地球化学特征的分析研究,认为它的成因颇为复杂,不仅具有冰碛岩的某些特征,而且还有重力流及滑塌沉积的一些特点。因此,凤台组可能是在冰前海湾(冰海)环境中的沉积。总之,这套杂砾岩显示出许多再沉积的特征。

The Upper Sinian Fengtai Formation distributed in Huainan and Huoqiu, western Anhui is represented by a clastic rock series dominated by diamictite with abundant carbonate rocks. It is a clastic rock series dominated by diamictite with abundant carbonate rocks. It is stratigraphically rougbly equivalent to the Luoquan Formation in western Henan. Divergent views have long existed as to the origin of the diamictite of the Fengtai Formation, but most researchers consider that it is glacial mcraine and glaciolacustrine deposits. According to the study of the sedimentary structure, petrology and geochemistry of the diamictite, the authors hold that its origin is rather complex. It has not only some features of tillite but also some features of gravity flow and slump deposits. Therefore the Fengtai Formation might be formed in a preglacial bay (glaciomarine) environment. In a word, the diamictite displays many redeposited features.