Ring Structure Characteristics of South Ordos Basin and Its Control Factors in the Deep

摘要

According to the synthetical analysis of remote sensing information and geophysical data, the late-reformation characteristics of the South Ordos basin in the Late Mesozoic and the Cenozoic is researched with the former research results and the field work. The result shows that the margin and inside of the basin are all reformed since late Mesozoic. Two different kinds of structure belt exist around the Ordos Basin. They are compressional thrust nappe belt and extensional faulted depression belt. The ring structure which is found in the southern Ordos basin has a diameter of more than 300km, and its movement and rotation are on the assumption that the ring has dominated by the mantle plume in the deep earth and relative movement on the surface of earth. It is testified that the ring structure is a relatively independent block, and it is significant for the coexistence of multi-energy resources in the same basin. There are also differences between the south and north part of Ordos basin in large scale lifting. That is the reason why there are differences between the south and north part of Ordos basin in the distribution of mineral resources. The seismic profile and the magnetotelluric sounding data of the ring structure show that there is a high depth of the Moho boundary comparing with the north part of Ordos basin, it convinced us that the mantle plume lifting does exist in the location of ring structure in the south part of Ordos basin. The lifting movement of Ordos basin in the Late Mesozoic and the Cenozoic may be an important factor of the changing channel of Yellow River cross the Ordos basin, it is significant for the formation and evolution of Yellow River.