[S-IT32] [EJ] Recent earthquakes and deep structure of the Earth in and around Tibetan Plateau

[SIT32-05] Density and magnetic intensity of the crust and
uppermost mantle across the northern
margin of the Tibetan Plateau

★Invited papers

*Junmeng Zhao¹, Shah Syed Tallataf Hussain¹, Heng Zhang¹, Xiankang Zhang², Changli Yao³, Yishi Li⁴, Hongbing Liu¹, Qiang Xu¹, Gong Deng¹, Zhaoguo Hu⁵, Zahid Imran Bhattib¹ (1.Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China, 2.Center for Geophysical Exploration, China Earthquake Administration, Zhengzhou 450002, China, 3.China University of Geosciences, Beijing100083, China, 4.China Earthquake Administration, Beijing100036, China, 5.Shandong Zhengyuan Institute of Geological Exploration, China Central Bureau of Metallurgy and Geology, Jinan 250000, China)

Keywords:Density, Geomagnetic intensity, Tibetan Plateau, Tarim Basin, Altyn Mountains, Qaidam Basin

Recently, we have processed the gravitational and geomagnetic data from a geophysical survey along a profile (Baicheng to Da Qaidam) which crosses the northern and eastern Tarim Basin, the Altyn Tagh Mountains, and the Qaidam Basin, respectively. Based on the P- and S-wave velocities (Zhao et al., 2006), both the density and magnetic intensity of the crust and uppermost mantle were determined by using a joint inversion of gravity versus geomagnetism. Our new results at the northern margin of the Tibetan Plateau reflect different crustal structures beneath Tarim basin and Qaidam basin, and these two basins may be produced by different terranes. In addition, strong deformation has occurred in the basement and interior of the Qaidam Basin during the tectonic evolution.