Structural features and tectonic stress fields of the Mesozoic and Cenozoic in the eastern margin of the Ordos basin,China

The structural features of the Mesozoic and Cenozoic in the eastern margin of the Ordos basin were studied.The results indicate that this field had influenced by the Indosinian movement,Yanshanian movement and Himalayan movement in Mesozoic and Cenozoic.The direction of tectonic stress field is nearly NS during the Indosinian movement,which is basically resulted from the collision between the Yangtze plate and the North China plate.During the Yanshanian movement,the structural styles of the eastern margin of Ordos basin were basically formed.As a result of far-field effects produced by subduction of the Paleo-Pacific plate beneath the Asian continent,a series of open gentle superficial folds stroke NE-NNE were developed in this field and Lishi fault was compressed from SE-SEE and characterized brittle deformation.During the Himalayan movement,the stress direction becomes NE-SW,and this is a result of far-field effects produced by the collision between the Indian plate and the Eurasian plate.