The Moho depth and variation character of the continent in China and its geodynamic implications

From the 1950s, lots of seismic exploration work has been implemented in the continent of China, which spread all over China’s main tectonic units. We summarized this datum systemically, and discussed the Moho depth and variation character in China. The Moho depth was sampled along 84 deep seismic sounding profiles per 20-30 km, and the datum of the receiver function and deep seismic reflection profile was added considering the blank exploration areas. The Moho depth and variation character shows that: the Moho framework of the continent in China is strongly correlated with China’s tectonics and topography, expressed in two weftwise and two warpwise strips. Two weftwise strips are Tianshan-Yinshan-Yanshan orogeny and Kunlun-Qilian-Dabie range, while two warpwise ones are Daxing’anling-Taihangshan-Wulingshan gravity gradient zone and Helanshan-Longmenshan range. According to the Moho framework of China and other geological evidences, the continent in China could be divided into three geodynamic domains: western domain, middle domain and eastern domain. The western one lies to the west of the Helanshan-Longmengshan range and is affected by the collision of Indian and Eurasian paltes, The main character is crustal thickening in the margin of the Tibet plateau, crustal thinning in the heartland of the plateau and reactivation of Tianshan orogeny; the middle zone lies between Helanshan-Longmenshan zone and Daxin'anling-Taihangshan-Wulingshan gravity gradient zone, this zone has stable crust and minor Moho variation relatively, which reflect a buffer zone between western and eastern zones and a transfer zone from compression to extension; the eastern zone is located to the east of the gravity gradient zone, mainly affected by the peri-Pacific tectonic domain, and the strong extensional and thinning event have changed the Moho depth and character in the entire eastern zone.