Rayleigh wave tomography of central and southern Mongolia

• Published in: Tectonophysics Vol. 836; p. 229426
• Main Authors: Wang, Xinglu, Wu, Hanting, Wang, Haibo, Wu, Benjun, Huang, Zhouchuan
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05.08.2022; Elsevier BV
• Subjects: Anomalies; Cenozoic; Cratons; Deserts; Domes; Far fields; Geological faults; Gobi Desert; Historical structures; Isotopes; Mantle upwelling; Mongolia; Ocean circulation; Paleozoic; Rayleigh waves; S waves; Seismic velocities; Slabs; Subduction (geology); Surface-wave tomography; Suture zones; Tectonics; Tomography; Upper mantle; Upwelling; Velocity; Wave velocity; Mongolia; Gobi Desert; Mongolia; Surface-wave tomography; Mantle upwelling; Suture zones; Gobi Desert
• ISSN: 0040-1951; 1879-3266
• DOI: 10.1016/j.tecto.2022.229426

The Mongolian Plateau located between the Siberian Craton and the North China Craton developed after multiple tectonic evolutions. It is proposed to be related to the far-field effect of the Indo-Asian collision in the Cenozoic. In this study, we inverted for high-resolution S wave velocity structures of Mongolia using Rayleigh wave tomography to constrain the plateau evolution. In particular, we obtained crustal and upper mantle seismic structures under Gobi Desert by combining Mongolian and Chinese datasets. The study reveals strong low-velocity anomalies in the lower crust immediately beneath the Hangay Dome, while the low-velocity zones are imaged beneath the dome margins in the upper mantle. The results imply that the Hangay Dome was formed by mantle upwelling into the crust from major faults following lithospheric delamination. Under the South Gobi Desert, we imaged several inclined high-velocity patches in the upper mantle, indicating the subducted slabs formed in the Paleozoic. The ancient structures in the upper mantle led the Indo-Asian collision to propagate further to southern Mongolia. •We obtained S wave velocities of the crust and upper mantle under Mongolia.•Low velocities under the Hangay Dome indicate the mantle upwelling.•The deep structures under the Gobi Desert are determined for the first time.•Ancient slabs are revealed beneath the South Gobi Desert.