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Receiver function (RF) analysis is an indispensable method that is widely utilized to image the deep structure of the crust and upper mantle. Although the P -wave receiver function (PRF) has the advantages of a higher signal-to-noise ratio and higher resolution than S -wave receiver function, the information about P -to- S converted (Ps) phases from velocity discontinuities of the crust and upper mantle is usually obstructed by multiples from shallower crustal interfaces. Sometimes it is difficult to identify useful information about lithospheric discontinuities. In this paper, we propose a method for suppressing multiples and isolating the Ps phases of RFs. This task is accomplished by exploiting the differences in arrival times resulting from the slowness between the conversion and the multiples that occur at the same interface in the PRFs and by separating them in the Radon domain, which enables removal of crustal and sedimentary multiples. This method can effectively remove multiples and isolate the useful signals of Ps phases contained in the PRFs. We test the method on synthetic PRFs and demonstrate that crustal multiples can be effectively eliminated or suppressed and that the Ps phase of lithospheric discontinuities can be coherently traced. Next, we apply the method to real PRF data collected from the seismic station of the China Array seismic experiment (Phase II and Phase III) in the Ordos block and its adjacent area, and successfully obtain an improved common conversion point stacking image of lithospheric discontinuity structures in the depth domain, particularly for detecting the lithosphere–asthenosphere boundary. [ABSTRACT FROM AUTHOR]

The Yinchuan-Hetao (YC-HT) graben is the boundary zone between the Ordos and the Alax blocks in NW China, which shows tectonic patterns distinct from the Haiyuan arcuate and Liupanshan thrust belts to the south. As a Cenozoic rift, the YC-HT graben originated from back-arc spreading related to westward subduction of the western Pacific, but its deformation and development may have been more influenced by the extension of the northeastern Tibetan Plateau (NETP) since the Quaternary. To investigate the dynamics of deep deformation of the YC-HT graben and adjacent regions, we apply the receiver function method to obtain the seismic structure in this area. Our results show that the depth of the Moho beneath the YC-HT graben is ∼50 km and significantly greater than that beneath the Alxa and Ordos blocks. The crust of the Ordos block is characterized by a layered structure, and the intracrustal structure below the YC-HT graben has undergone significant deformation. The Vp/Vs ratio in a local area of the western Hetao graben is as high as ∼1.9. By combining our observations with previous geophysical and geological studies, we speculate that the influence of NETP expansion has reached the YC-HT graben at depth. Meanwhile, the upper and lower crust experienced different deformation modes in this area, which manifested as elastic deformation in the upper crust and plastic deformation in the lower crust. [Display omitted] • Crustal velocity discontinuity structure and Vp/Vs ratios are obtained in the northwestern border of the Ordos, NW China. • Thickened crust and high Vp/Vs anomalies in the crust dominate the Yinchuan-Hetao graben. • Upper and lower crust beneath the Yinchuan-Hetao graben have undergone extensional and thickening deformation respectively. [ABSTRACT FROM AUTHOR]