Crustal and upper mantle structure beneath Abaga area in Inner Mongolia revealed by Rayleigh-wave phase velocity tomography

作     者：Jie Hou Qing-Ju Wu Da-Xin Yu Qing-Dong Ye Jie Hou;Qing-Ju Wu;Da-Xin Yu;Qing-Dong Ye

作者机构：Institute of GeophysicsChina Earthquake AdministrationBeijing 100081China The First Monitoring and Application CenterChina Earthquake AdministrationTianjin 300180China 

出 版 物：《Earthquake Science》 (地震学报（英文版）)

年 卷 期：2019年第32卷第5期

页      面：207-220页

学科分类：070801[理学-固体地球物理学] 07[理学] 0708[理学-地球物理学] 

基　　金：National Natural Science Foundation of China(Nos.41674094 and 41504073) 

主　　题：Solonker suture zone Darigan Volcano phase velo-city surface-wave tomography Rayleigh wave 

摘      要：There are strong interactions between the crust and the mantle in the Abaga *** study the structure of the crust and upper mantle in that area,the fundamental-mode Rayleigh-wave phase velocity dispersion along 3,331 inter-station paths were estimated by the continuous wavelet transformation *** dispersion data were used to construct the first 2-D phase velocity maps for waves with periods of 12-80 s and a horizontal resolution of 0.5°×0.5°by applying a linear *** results show that the short-period phase velocity distributions(12-20 s)are affected by exposed Cenozoic volcanoes and the thickness of the sedimentary *** velocity maps for waves with periods of 30-40 s indicate that the direction of the Solonker suture zone is in good agreement with the extension of the high-speed anomalous connection in the study *** is concluded that the Solonker suture zone extends throughout the entire *** periods of 30-80 s,stable low-velocity anomalies were observed near the Holocene volcanoes in the northeast and south of the study area,suggesting that the low-velocity anomaly is related to volcanic ***,the two low-velocity anomalies may be connected,suggesting that the Darigan Volcano may have the same thermal source as the Honggeertu Volcano and even the Datong *** the thermal source of the two low-velocity anomalies is speculated to be upwelling of hot mantle *** addition,the velocities in the crust and upper mantle are lower than those from the AK 135 model and are close to the velocity for the destroyed North China Craton,and very similar to that for the East African Rift *** may indicate that the lithospheric structure in the Abaga area is active.