鄂尔多斯盆地北部中新生代构造特征及其演化

根据地震、地质等资料,结合野外地质及前人研究成果,对鄂尔多斯盆地北部中生代晚期以来后期改造特征进行了研究。结果表明,盆地周缘和内部在中新生代都受到后期改造作用,周缘存在挤压逆冲推覆和拉张断陷等不同性质的构造改造作用。在盆地北部,盖层中的构造受到了基底断裂的控制,正断层、逆断层和由基底断裂控制的挠曲构造等有规律发育,根据构造的发育特点将盆地北部分为东胜、三眼井、准格尔旗、鄂托克旗、乌审旗—榆林和定边—绥德构造区。自侏罗纪以来,盆地经历了萎缩消亡和周缘逆冲构造带的形成、挤压隆升剥蚀和拉张隆升剥蚀3大构造演化阶段,现今构造是中新生代多期构造作用的结果。

Structural Characteristics and Evolution of North Ordos Basin in Late Mesozoic and Cenozoic

The structural characteristic of the North Ordos basin in the Late Mesozoic and the Cenozoic is researched with the data of seismic,geological and former achievements.The result shows that the margin and inside of the basin are all reformed since late Mesozoic.There exist compressional thrust nappe belt and tensional faulted depression belt around the Ordos basin.In northern basin,structures developed in cover strata are controlled by basement faults.Normal faults,reverse faults and flexural structures are developed regularly.Six structural areas,Dongsheng,Sanyanjing,Zhungeer,Etuokeqi,Wushenqi-Yulin and Dingbian-Suide,are recognized according to their respective structural characteristics.Since the Jurassic,basin evolution can be divided into three stages of basin die-out and thrust nappe formation,compressional uplift and erosion,tensional uplift and erosion.The present structure in the north baisn is the result of multi-events from the Jurassic to present.