Study on the deep structure of the northeastern margin of the Qinghai-Tibet Plateau based on gravity, magnetic, and electrical methods

The collision between the Indian and Eurasian plates has led to the expansion and uplift of the Qinghai-Tibet Plateau, significantly impacting the topography and hydrological patterns in Asia. This process has also notably altered the global distribution of climate, creating the vast arid region of northwest Asia. Seismic activity is frequent along the northeastern margin of the Qinghai-Tibet Plateau due to the compression of plates, posing significant challenges to the social development and national economy of the ‘Belt and Road Initiative’ Silk Road Economic Belt region. The southern part of the Alashan Block, positioned at the northeastern extension of the Qinghai-Tibet Plateau, presents a unique geological window for studying this extension. Previous studies have focused on the northeastern extension of the Qinghai-Tibet Plateau at both ends, exploring various aspects such as geomorphic boundaries, shallow deformation boundaries, and deep structural configurations. However, a unified understanding is yet to be achieved. This paper aims to utilize geophysical techniques to investigate the deep structure of the Tengger region in the southern Alashan Block, considering the complex surface conditions of desert cover. Combining geological research, the study will particularly emphasize the nature of near-surface sedimentary cover layers, crystalline basement structures, changes in deep crustal structures, and the relationship between shallow and deep structures. The findings of this research hold significant scientific importance in understanding the processes of the Qinghai-Tibet Plateau's Neogene uplift expansion, comprehending regional and global geomorphic evolution, seismic mechanisms, among others.