摘要：

陕甘宁地区位于华北地台西部，处于东西构造域的交接部位，是我国重要的含煤、油气区之一。受不同构造背景、海平面升降、沉积物供给等影响，其晚古生代沉积体系类型多样。通过对露头、岩心、测井响应及编图等分析研究，区分出了碳酸盐台地、障壁岛－湖潮坪、潮道－湖潮坪、河控三角洲、扇三角洲、河流、冲积扇、湖泊等沉积类型，阐明了各自的沉积特征。晚古生代沉积体系展布、充填演化与南北两侧的兴蒙海槽和秦祁海槽的构造活动密切相关：晚石炭世西缘拗拉槽重新复活，形成以潮道－湖潮坪沉积为主的海湾充填，充填受基底和盆缘断裂控制；早二叠世东西部海水汇合，本区统一于华北陆表海中,形成碳酸盐台地、障壁岛、浅水三角洲交互的含煤沉积；中二叠世至晚二叠世早期陆表海萎缩，本区演变为近海内陆坳陷充填，形成冲积扇、河流、三角洲、湖泊沉积；晚二叠世晚期陆表海消亡，本区转化为内陆坳陷，形成以湖泊沉积为主的河湖充填。砂储层发育取决于沉积环境，空间展布受控于古构造机制。

Abstract:

Shaanxi－Gansu－Ningxia area is located at the western part of North China platform and the conjoining part of east and west tectonic area, and is one of the most important oilgasbearing area in China. Influenced by alternative tectonic background, eustatism and sediments supply, the Late Palaeozoic depositional system types are diverse. Through the synthetic study of field outcrops, well core, logging and mapping, depositional system types have been identified, including carbonate platform, barrier islandlagoon and tidal flat, tidal channellagoon and tidal flat, river delta, fan delta river, lake, alluvial fan systems. The distribution and filling evolution of the Late Palaeozoic depositional system were related closely with the tectonic activity of the Xingmeng Trough and the QinlingQilian Trough. Controlled by basement and basin marginal fracture, the aulacogen at the western border revived at the Late Carboniferous and formed estuary filling of tidal channellagoon and tidal flat deposits. At the Early Permian sea water of east and west parts joined together to form an united NorthChina epicontinental sea and the coalbearing deposits were formed in environments of carbonate platform, barrier island and shallow water delta in the study area. During the Middle－early Late Permian the epicontinental sea contracted and evolved into a paralic inland depression in the study area and alluvial fan, river, delta and lake facies were formed. During the late LatePermian the epicontinental sea extincted and this area evolved into an inland depression and formed riverlake fillings, mainly lake facies. The development of sandy reservior were controlled by sedimentary environments and its spatial distribution was controlled by palaeotectonic mechanism.