Composition model of the crust beneath the Ordos basin and the Yinshan mountains in China, based on seismic velocity, heat flow and gravity data

• We present the new geophysical research result in the OB and the YSM.
• We review our knowledge of the crust from both field-based and sample-based studies.
• We derive the probable lithologic composition model of the OB and the YSM.
• We analyze the differences between the OB and the YSM.

In this paper, we have constructed a composition model of the crust beneath the Ordos basin and the Yinshan mountains in north China, with reference to the seismic velocity, heat flow and gravity data measured along the 650-km geophysical profile in the direction of N–S from Yanchuan county in the Ordos basin to Mandula town on the north side of the Yinshan mountains. In order to get this model, we have corrected the crustal physical parameters measured along the profile into the data under the pressure of 600 MPa and room temperature (20 °C), which we can use to compare with the data measured in laboratory under the same pressure and temperature conditions. Inversion of the geophysical data set to rock compositions indicates that the composition of the crust along the Yanchuan–Mandula profile reveals difference in the Ordos basin and the Yinshan mountains respectively. In general, the composition model of the crust beneath the Yanchuan–Mandula profile generally varies significantly in vertical direction but slightly in lateral direction. The heterogeneity of the distribution of lithologic composition exists mainly in the coupling zone between the Ordos basin and the Yinshan mountains.