摘要:原型盆地恢复有助于盆地构造—岩相古地理的研究和揭示盆山耦合，对油气勘探与开发具有重要的指导意义。本文利用最新的钻井、测井及露头资料，以沉积相为研究实体，运用盆—山结合的思路，由点—线—面进行分析，重建了鄂尔多斯盆地晚石炭世本溪组沉积时期的构造—沉积环境，研究了原型盆地特征及性质。本溪组沉积期，鄂尔多斯盆地沉积具有东西分异的特征：淳化—庆阳—吴起地区及北部伊盟地区为暴露剥蚀区，东部为克拉通内坳陷盆地，西部为克拉通边缘裂陷盆地。乌达—呼鲁斯台及鄂尔多斯—神木地区发育三角洲相，并向南逐渐推进；鄂西石嘴山、环县及鄂东府谷、延安地区以环带状潮坪—泻湖相为主，受间歇性海侵影响；吴忠、柳林—吉县地区发育低能的泻湖相；中卫—中宁、韩城及以东地区发育不同深度的陆棚及开阔台地。该时期盆地构造环境表现为南北向双向俯冲、贺兰拗拉槽再活化，格局经历了南隆北倾向北隆南倾的转变。受此影响，鄂尔多斯盆地构造古地理格局开始由东西分异逐渐向南北分异转变，受东西两侧海侵影响沉积相带呈环带状展布，但在盆地北部发育潮控三角洲，表现出近缘特征。晚石炭世鄂尔多斯盆地构造—沉积环境与原型盆地特征与其对周缘大地构造运动的响应。
关键词: 本溪组/
原型盆地/
构造—沉积环境/
鄂尔多斯盆地
Abstract:The recovery of prototype basin is helpful to the study of basin structure lithofacies paleogeography and the discovery of basin mountain coupling, which is of great significance to the exploration and development of oil and gas. Based on the newest data of drilling, logging and outcrops data, with the analysis of sedimentary facies and the combination with basins and orogenic belts, this paper reconstructed tectonic-depositional environment during the depositional period of the Late Carboniferous Benxi Formation in the Ordos Basin, and analyzed the features and properties of the basin by utilizing the method of "point-line-planar". During the depositional period of Benxi Formation, the sedimentary pattern exhibited the feature of the east-west differentiation in the Ordos Basin, and the Chunhua-Qingyang-Wuqi area was denudated. The craton inner depression basin is in the east and the craton marginal rift basin is in the west. The delta facies developed in the Wuda-Hulusitai and Erdos-Shenmu areas and gradually advanced southward. Shizuishan, Huanxian and Fugu, Yanan are dominated by tidal flat and lagoon facies, which are affected by intermittent transgression. Low energy lagoon facies developed in Wuzhong, and Liulin-Jixian area. There are shelf facies and open platform in different depth in Zhongwei-Zhongning, Hancheng and eastern area. During this period, the tectonic environment of the basin was characterized by bi-directional subduction from south and north and reactivation of Helan aulacogen, and the pattern experienced the change of the north inclination of the south uplift. As a result, the tectonic paleogeographic pattern of the Ordos Basin began to change from east-west differentiation to north-south differentiation, and the sedimentary facies were distributed in a circular belt under the influence of the transgression on both the east and west sides. The tectonic-depositional environment and prototype basin during the depositional period of the Late Carboniferous Benxi Formation in the Ordos Basin was a response to peripheral tectonic movements．
Key words:Prototype basin/
Tectonic-depositional environment/
Benxi Formation/
Late Carboniferous
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