The Study Of Geophysical Characteristics And Tectonic Frame In Eastern And Central Inner Mongolia

Deep Fractures are main ore-controlling structures. Eastern and central inner Mongolia located in North China craton and Siberia plate, where grows several deep fractures. There are still exist many problems in tectonic frame and the site of plate subduction zone.Geologists had reached a consensus: Siberia plate and North China craton closed before Early Mesozoic. Before Early Mesozoic, Eastern and central Inner Mongolia is divided into Dongwu—Huma stratigraphic subregion, Xinlinhaote—Panshi stratigraphic subregion and Chifeng stratigraphic subregion. Their boundaries are buried fractures or subductions. In this paper, we discuss the similarity and difference sedimentary environment and geophysical characteristics. On the basis of strata, we can figure out that these three stratigraphic subregions were all in shallow sea—littoral—interactive marine & terrestial environment. And the main cause of gravity and magenetic anomaly is Baoligaomiao Fm in Dongwu—Huma stratigraphic subregion, magmatic rock grew in early Caledonian, Variscan and late Yanshanian.Wide angle reflection and refraction seismic method was used in geoscience transection from Dongwuzhumuqinqi to Donggou in Liaoning province. Geophysical data shows that structure of the velocity distribution of crust across the deep fracture of Xar Moron River exist obvious differences. And earth upper mantle jump from Wengteniuqi to Wufendi near Xar Moron River. Combined with geological data, we figure out that the deep fraction of Xar Moron River is the subduction zone of North China craton and Siberia plate. According to gravity and magenetic anomaly, we divided this area into six tectonic zone, explain how these anomalies generated and map the structures.The central Xilinhaote—Panshi stratigraphic subregion has low gravity anomaly and magenetic anomaly. Gravimetric inversion of the section from Xiwuzhumuqinqi to Balinyouqi demonstrate that the thickness of Paleozoic is more than 8 km. Near Xar Moron River, magmatic rock developed and share the same channel.