苏浙皖地区茅口阶和上二叠统沉积相

Maokouan and Upper Permian sedimentary facies in the Jiangsu-Zhejiang-Anhui region

关键词:  沉积相  茅口阶和上二叠统  苏浙皖

Key words:  sedimentary facies  Maokouan and Upper Permian  Jiangsu-Zhejiang-Anhui region

摘要:

苏浙皖地区茅口阶和上二叠统各组普遍穿时。进入茅口期,一改栖霞期广袤平坦的碳酸盐台地面貌,三角洲、浅海和碳酸盐台地分割清楚,来自华夏古陆和鲁东古陆的碎屑和清水的底栖生物成为塑造全区古地形的主要物质。冷坞海绵圆丘礁微相展布显示区域古地理格局,区内孤峰组生物—岩相变化揭示茅口期早时古地理差异。上二叠统陆屑明显减少,全区呈现碳酸盐台地和陆棚两个相带,其切变部位可能是江南断裂确切位置。

Abstract:

The Maokouan and Permian formations in the Jiangsu-Zhejiang-Anhui region are mostly diachronous. During the Maokouan stage,a vast expanse of Qixian carbonate platforms disappeared,instead the deltas,shallow seas and carbonate platforms were well defined. The debris were mainly derived from the Cathaysian and East Shandong ancient land,and the clear-water benthic organisms were widespread throughout the study area. The distribution of the Lengwu sponge knoll reef microfacies has also discolsed the palaeogeographic features in this area. The variations in biofacies and lithofacies in the Gufeng Formation have reflected the palaeogeographic differences during he early Maokouan. the terrigenous clastics apparently decreased in the Late Permian. There existed two facies belts,i, e. the carbonate platform and continental shelf facies belts,and the boundary between them may be exact position of the Jiangnan fault.