Abstract: The Middle Permian Shanxi Formation of Henan Province developed a set of deposits of littoral facies and delta facies characterized by the clastic coal measures，which is the important coal-bearing strata during the Late Paleozoic in Henan Province.Based on the isoline trend analysis of thickness of the formation and the sand-mud ratio，as well as distribution features of facies fossils and sedimentary assemblage types，four sedimentary facies including lagoon（bay） facies,tidal-flat facies,barrier island facies and delta facies can be distinguished and three types of lithofacies areas can be divided，including the delta sandstone and mudstone lithofacies，bay（lagoon）-tidal flat siltstone and mudstone lithofacies，and barrier island-tidal flat-lagoon（bay）sandstone and mudstone lithofacies.The Middle Permian palaeotopography of Henan Province displays a higher terrain in the north and west，and a lower terrain in the south and east，and there exists a palaeo-uplift area under water in central section，therefore， the regression occurred from northwest to southeast within this province；Old land are situated along the Funiu Mountain in southwestern Henan and Zhongtiao Mountain in western Henan，thereout，there are two sedimentary areas of the largest thickness of this formation that lie in the northeastern and eastern of Henan Province.It is possible to infer that provenance is from the western old land（Zhongtiao Mountain） which is shown evidently in the lithofacies palaeogeographic map.

Key words: lithofacies palaeogeography, sedimentary facies, Shanxi Formation, Middle Permian, Henan Province

摘要： 河南省中二叠统山西组发育了一套以陆源碎屑含煤岩系为特色的滨海相、三角洲相沉积，是河南省晚古生代的重要含煤地层。基于地层厚度、砂泥比等值线的变化趋势分析以及指相化石和沉积组合类型的分布特征，可以确定出4种沉积相：潟湖（海湾）相、潮坪相、障壁岛相和三角洲相；划分出3种岩相区：三角洲泥岩及砂岩相区，海湾（潟湖）—潮坪粉砂岩及泥岩相区和障壁岛—潮坪—潟湖（海湾）砂岩及泥岩相区。当时的沉积古地理特征表现为：豫西南为伏牛古陆，豫西为中条古陆，总体地势呈北西高，南东低，中部有一水下隆起区；海水由西北向东南方向退去；物源主要来自盆地西侧的中条古陆；最大厚度沉积区位于东北部及东部。

关键词: 岩相古地理, 沉积相, 山西组, 中二叠统, 河南省

CLC Number: 

• P531