TY - JOUR
T1 - High-resolution lithospheric structure beneath Mainland China from ambient noise and earthquake surface-wave tomography
AU - Bao, Xuewei
AU - Song, Xiaodong
AU - Li, Jiangtao
N1 - Funding Information:
The seismic waveform data were provided by Data Management Centre of China National Seismic Network at Institute of Geophysics, China Earthquake Administration ( Zheng et al., 2010 ) and Data Management Center at the Incorporated Research Institution of Seismology. Most figures were prepared using Generic Mapping Tools (GMT) ( Wessel and Smith, 1998 ). This research was supported by the National Science Foundation of China ( 41274056 and 41330209 ), China Postdoctoral Science Foundation ( 2012M521046 ), US National Science Foundation ( EAR 1215824 ), and Department of Geology, University of Illinois at Urbana-Champaign .
PY - 2015/5/1
Y1 - 2015/5/1
N2 - We present a new high-resolution shear-velocity model of the lithosphere (down to about 160 km) beneath China using Rayleigh-wave tomography. We combined ambient noise and earthquake data recorded at 1316 seismic stations, the largest number used for the region to date. More than 700,000 dispersion curves were measured to generate group and phase velocity maps at periods of 10-140 s. The resolution of our model is significantly improved over previous models with about 1-2° in eastern China and 2-3° in western China. We also derived models of the study region for crustal thickness and averaged S velocities for upper and mid-lower crust and uppermost mantle. These models reveal important lithospheric features beneath China and provide a fundamental data set for understanding continental dynamics and evolution. Different geological units show distinct features in the Moho depth, lithospheric thickness, and shear velocity. In particular, the North China Craton (NCC) lithosphere shows strong east-west structural variations with thin and low-velocity lithosphere in eastern NCC and thick and high-velocity lithosphere beneath western NCC and the lithosphere of the Ordos Block seems to have undergone strong erosion. The results support the progressive destruction of the NCC lithosphere from east to west at least partly caused by the thermal-chemical erosion of the cratonic lithosphere from the asthenosphere. Another pronounced feature of our model is the strong lateral variations of the mantle lithosphere beneath the Tibetan Plateau (TP). The Indian lithosphere beneath the TP shows variable northward advancement with nearly flat subduction in western and eastern TP and steep subduction in central TP with evidence for the tearing of Indian lithosphere beneath central TP, which may be important for the riftings at the surface in Himalayas and southern TP. The low-velocity zone in northern TP shows strong correlation with the region of the mid-Miocene to Quaternary potassic magmatism, suggesting that delamination of lithosphere may have played an important role in the rise of the TP.
AB - We present a new high-resolution shear-velocity model of the lithosphere (down to about 160 km) beneath China using Rayleigh-wave tomography. We combined ambient noise and earthquake data recorded at 1316 seismic stations, the largest number used for the region to date. More than 700,000 dispersion curves were measured to generate group and phase velocity maps at periods of 10-140 s. The resolution of our model is significantly improved over previous models with about 1-2° in eastern China and 2-3° in western China. We also derived models of the study region for crustal thickness and averaged S velocities for upper and mid-lower crust and uppermost mantle. These models reveal important lithospheric features beneath China and provide a fundamental data set for understanding continental dynamics and evolution. Different geological units show distinct features in the Moho depth, lithospheric thickness, and shear velocity. In particular, the North China Craton (NCC) lithosphere shows strong east-west structural variations with thin and low-velocity lithosphere in eastern NCC and thick and high-velocity lithosphere beneath western NCC and the lithosphere of the Ordos Block seems to have undergone strong erosion. The results support the progressive destruction of the NCC lithosphere from east to west at least partly caused by the thermal-chemical erosion of the cratonic lithosphere from the asthenosphere. Another pronounced feature of our model is the strong lateral variations of the mantle lithosphere beneath the Tibetan Plateau (TP). The Indian lithosphere beneath the TP shows variable northward advancement with nearly flat subduction in western and eastern TP and steep subduction in central TP with evidence for the tearing of Indian lithosphere beneath central TP, which may be important for the riftings at the surface in Himalayas and southern TP. The low-velocity zone in northern TP shows strong correlation with the region of the mid-Miocene to Quaternary potassic magmatism, suggesting that delamination of lithosphere may have played an important role in the rise of the TP.
KW - Ambient noise correlation
KW - Lithosphere
KW - North China craton
KW - Rayleigh wave tomography
KW - Tibetan plateau
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U2 - 10.1016/j.epsl.2015.02.024
DO - 10.1016/j.epsl.2015.02.024
M3 - Article
AN - SCOPUS:84922375445
SN - 0012-821X
VL - 417
SP - 132
EP - 141
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
ER -