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Internal Deformation of Lithosphere Beneath Central Tibet
Author(s) -
Zhang Heng,
Zhao Dapeng,
Zhao Junmeng,
Hu Zhaoguo
Publication year - 2017
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.983
H-Index - 232
eISSN - 2169-9356
pISSN - 2169-9313
DOI - 10.1002/2017jb014184
Subject(s) - geology , lithosphere , anisotropy , crust , mantle (geology) , deformation (meteorology) , seismology , fibrous joint , seismic anisotropy , geophysics , tectonics , optics , anatomy , physics , medicine , oceanography
We use a large number of high‐quality P wave arrival time data recorded by the Hi‐CLIMB project to determine a 3‐D model of azimuthal anisotropy tomography beneath central Tibet. In the Himalayan block, variations of fast velocity orientation (FVO) are revealed from the crust to the upper mantle. In contrast, the FVO in the Lhasa block exhibits only a slight difference between the lower crust and upper mantle, reflecting a coherent deformation there. Different FVOs are revealed near the Bangong‐Nujiang suture, which may reflect anisotropies in different parts of the underthrusting Indian plate. In the upper mantle beneath the Qiangtang block, a strong anisotropy is revealed in the shallower part, whereas a weak anisotropy appears in the deeper part, suggesting that a two‐layer anisotropy model is applicable there. A layered lithosphere is detected in the eastern part of the Lhasa block, whereas a consistent FVO is revealed in its western part. Our results indicate that strong deformation has occurred in both the Indian and Eurasian lithospheres.