1. College of Geosciences and Engineering,Xi’an Shiyou University,Xi’an 710065,China 2. Shaanxi Academy of Geological Survey,Xi’an 710014,China 3. Bureau of Xi’an Geological Survey,China Geological Survey,Xi’an 710054,China 4. College of Software, Northwestern Polytechnical University,Xi’an 710072,China
The structure in the west of the Weihe Basin is complex. At present, there are different views on the basic geological problems in such aspects as the division of the tectonic units, the characteristics of stratigraphic development and the properties of basement. In this study, the distribution characteristics and basement properties of the sedimentary strata in the western part of Weihe Basin were inferred by using four newly implemented magnetotelluric (MT) sounding profiles in Baoji area, in combination with the gravity data and through the comprehensive interpretation of gravity and electricity. The results show that, along the route from Longxian to Fengxiang, the resistivity anomaly is low, the gravity is high, the Cenozoic sediments are thin, and the basement is shallow. The Cretaceous strata are exposed in some areas, and the basement of the area is dominated by the Mesozoic strata. In Qianyang area, there are high resistivity value and high gravity value, and the surface outcrop is complex. There exist Cambrian, Ordovician, Triassic, Cretaceous, Jurassic and some other strata, and the basement is composed of Mesozoic-Paleozoic-Proterozoic strata. In the west of Fufeng, south of Qishan, the resistivity value drops sharply from the north and south sides, and the basement is assumed to be composed of metamorphic rocks. The northern part of Baoji to Meixian area is characterized by high resistivity and gravity, and the northern part of Baoji to Meixian area has partly exposed Cretaceous strata with Paleozoic-Proterozoic basement. The south of Baoji to Meixian area is characterized by high resistivity and low gravity. There is a large area of granite outcrops, with the basement composed of granite.
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