宁夏中卫晚石炭世沉积相分析与古环境重建

Facies Analysis and Sedimentary Environment Reconstruction of the Late Carboniferous in Zhongwei,Ningxia

宁夏中卫地处北祁连加里东褶皱带东段 ,出露有连续而发育完好的晚石炭世海陆交互相含煤地层。根据岩性、颜色、粒度分析、沉积相标志、地球化学特征以及结合古生物化石资料 ,对中卫下河沿地区晚石炭世红土洼组、羊虎沟组和太原组的沉积相进行了分析研究 ,确立并划分出泻湖、潮坪、支间湾河口坝、滨海沼泽及三角洲平原等沉积相。在此基础上 ,结合本地区的古地理背景对宁夏中卫的晚石炭世的古沉积环境进行了重建。

The Late Carboniferous marine and non marine alternating deposits are well developed and outcropped in Xiaheyan of Zhongwei County, Ningxia Hui Autonomous Regionnorthwest China, including the Hongtuwa, Yanghugou and Taiyuan Formations. The facies analysis and sedimentary environment evolution are investigated in this study based on evidences of lithology, color, granularity analysis, facies indicator, geochemical data as well as fossil fauna and flora and Spore Pollen assemblages. Five facies are recognized including lagoon, tide flat, distributary bay estuarine sandbar, seashore and lowland marsh and tidal plainas well. In addition, the palaeogeographical background and sedimentary environmental evolution in Zhongwei of Ningxia are revealed and reconstructed based upon comparisons of the sedimentary characteristics with adjacent regions, including Eastern Sector of North Qilian, Ordos Basin and Taiyuan area of Northern China.