江南造山带东段新元古代双桥山群沉积环境分析

THE SEDIMENTARY ENVIRONMENT ANALYSIS OF THE NEOPROTEROZOIC SHUANGQIAOSHAN GROUP IN EASTERN SECTOR OF JIANGNAN OROGEN

江南造山带东段经公桥地区新元古代双桥山群地层保存较为完整,对经公桥地区双桥山群的横涌组、计林组以及安乐林组进行剖面测量,根据野外沉积构造、沉积层序特征,结合室内薄片鉴定和粒度分析对经公桥地区双桥山群的沉积环境进行研究,认为双桥山群沉积相为海底扇相,其中横涌组为中扇亚相、计林组为外扇亚相、安乐林组为中扇亚相。双桥山群由下至上的沉积特征指示水体变化趋势为浅-深-浅。

The strata of the Neoproterozoic Shuangqiaoshan Group in Jinggongqiao area in the eastern sector of Jiangnan Orogen are preserved relatively completely. This paper presents results based on the sedimentary analyses of the Hengyong Formation, Jilin Formation and Anlelin Formation in Shuangqiaoshan Group. The data suggest that the Shuangqiaoshan Group deposited in the submarine fan facies, among which the middle fan subfacies represented by the Hengyong and Anlelin formations, and outer fan subfacies represented by the Jilin Formation. Overall, the Shuangqiaoshan Group shows a characteristic shallow-deep-shallow upward sedimentary sequence.