Shallow Structure of the Crust in the Sulu-Dabie Region,China and its Seismotectonic Implication |
| |
| Authors: | XU Jiren LI Haibing QI Xuexiang ZHAO Zhixin |
| |
| Institution: | 1 Jiangsu Donghai-Sichuan Longmenshan Crustal Activity National Observation and Research Station, Donghai, Jiangsu 222300, China
2 Key Laboratory of Deep-Earth Dynamics, Ministry of Natural Resources, Beijing 100037, China
3 Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China |
| |
| Abstract: | The P-wave velocity structure in the shallow crust is investigated in and around the Sulu-Dabie region by using seismic reflection data for deep soundings in 48 survey profiles and from rock velocity determinations. The observed velocity distributions show obvious heterogeneities in this region. The low velocity anomalies are observed mainly in the west of the Dabie region and the East Sea regions. The high velocity anomalies emerge in the shallow crust of the Sulu and Dabie orogeny. These high-velocity anomalies can be attributed to the ultra-high pressure metamorphosed (UHPM) rock formed by exhumation motion of mantle materials during the orogeny. The high-velocity anomalies in the different shallow layers beneath the Sulu region are located to the northeast of the Tan-Lu fault. The high-velocity anomalies beneath the Dabie region are located southwest of the Tan-Lu fault. Such a distribution pattern of velocity anomaly zones may reveal historical motion of a left-lateral strike-slip for the Tan-Lu fault, which differs from the result of a right-lateral strike-slip motion regime known from modern seismology, indicating a more complex tectonic motion along the Tan-Lu fault. |
| |
| Keywords: | high seismic velocity anomaly shallow crust strike-slip motion Tan-Lu fault Sulu-Dabie orogen |
| 本文献已被 CNKI 等数据库收录！ |
| 点击此处可从《Acta Geologica Sinica》浏览原始摘要信息 |
| 点击此处可从《Acta Geologica Sinica》下载免费的PDF全文 |
