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-reformationcharacteristics of the South Ordos basin in the Late Mesozoic and the Cenozoic is researched with the formerresearch results and the field work. The result shows that the margin and inside of the basin are all reformedsince late Mesozoic. Two different kinds of structure belt exist around the Ordos Basin. They are compressionalthrust nappe belt and extensional faulted depression belt. The ring structure which is found in the southern Ordosbasin has a diameter of more than 300km, and its movement and rotation are on the assumption that the ring hasdominated by the mantle plume in the deep earth and relative movement on the surface of earth. It is testifiedthat the ring structure is a relatively independent block, and it is significant for the coexistence of multi-energyresources in the same basin. There are also differences between the south and north part of Ordos basin in largescale lifting. That is the reason why there are differences between the south and north part of Ordos basin in thedistribution of mineral resources. The seismic profile and the magnetotelluric sounding data of the ring structureshow that there is a high depth of the Moho boundary comparing with the north part of Ordos basin, it convincedus that the mantle plume lifting does exist in the location of ring structure in the south part of Ordos basin. Thelifting movement of Ordos basin in the Late Mesozoic and the Cenozoic may be an important factor of thechanging channel of Yellow River cross the Ordos basin, it is significant for the formation and evolution ofYellow River.