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.