TY - JOUR
T1 - Wedge tectonics in South China
T2 - constraints from new seismic data
AU - Li, Tingzi
AU - Jiang, Mingming
AU - Zhao, Liang
AU - Yao, Weihua
AU - Chen, Ling
AU - Chu, Yang
AU - Sun, Baolu
AU - Ai, Yinshuang
AU - Wan, Bo
AU - Gessner, Klaus
AU - Yuan, Huaiyu
PY - 2022/7/30
Y1 - 2022/7/30
N2 - Collisional orogens form when tectonic forces amalgamte fragments of Earth's continental lithosphere. The sutures between individual fragments, or terranes, are potential sites of weakness that facilitate subsequent continental breakup. Therefore, the lithospheric architecture of collisional orogens provides key information for evaluating the long-term evolution of the continental interior: for example, the South China Block (SCB), where the tectonic history is severely obscured by extensive surface deformation, magmatism, and metamorphism. Using new passive-source seismic models, we show a contrasting seismic architecture across the SCB, with three prominent crustal dipping structures across the Jiangnan Orogen. Combined with constraints from multi-disciplinary regional geophysical datasets, these pronounced dipping patterns are interpreted as relict wedge-like lithospheric deformation zones initiated in the fossil collisions that assembled the Yangtze Block and the SCB. The overall trend of these tectonic wedges implies successive crustal growth along paleo-continental margins and is indicative of northward subduction and docking of accretional terranes. In contrast, no such dipping structures are preserved in the Cathaysia Block, indicating a weak and reorganized lithosphere. The variations in the deformation responses across the SCB reflect the long-term modifications of the lithosphere caused by prolonged collision and extension events throughout the tectonic history of the SCB. Our results demonstrate the critical roles that suture zones played in the successive growth and evolution of the continental lithosphere.
AB - Collisional orogens form when tectonic forces amalgamte fragments of Earth's continental lithosphere. The sutures between individual fragments, or terranes, are potential sites of weakness that facilitate subsequent continental breakup. Therefore, the lithospheric architecture of collisional orogens provides key information for evaluating the long-term evolution of the continental interior: for example, the South China Block (SCB), where the tectonic history is severely obscured by extensive surface deformation, magmatism, and metamorphism. Using new passive-source seismic models, we show a contrasting seismic architecture across the SCB, with three prominent crustal dipping structures across the Jiangnan Orogen. Combined with constraints from multi-disciplinary regional geophysical datasets, these pronounced dipping patterns are interpreted as relict wedge-like lithospheric deformation zones initiated in the fossil collisions that assembled the Yangtze Block and the SCB. The overall trend of these tectonic wedges implies successive crustal growth along paleo-continental margins and is indicative of northward subduction and docking of accretional terranes. In contrast, no such dipping structures are preserved in the Cathaysia Block, indicating a weak and reorganized lithosphere. The variations in the deformation responses across the SCB reflect the long-term modifications of the lithosphere caused by prolonged collision and extension events throughout the tectonic history of the SCB. Our results demonstrate the critical roles that suture zones played in the successive growth and evolution of the continental lithosphere.
KW - Ambient noise tomography
KW - Lithosphere architecture
KW - Seismic receiver functions
KW - South China Block
KW - Wedge tectonics
UR - http://www.scopus.com/inward/record.url?scp=85133656446&partnerID=8YFLogxK
U2 - 10.1016/j.scib.2022.05.007
DO - 10.1016/j.scib.2022.05.007
M3 - Article
C2 - 36546193
AN - SCOPUS:85133656446
SN - 2095-9273
VL - 67
SP - 1496
EP - 1507
JO - Science Bulletin
JF - Science Bulletin
IS - 14
ER -