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Journal: |
Journal of Geophysical Research 2018 No.10
clicks:141 |
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Title:
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Author:
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Zhouchuan Huang1,2 , Liangshu Wang1 , Mingjie Xu1 , and Dapeng Zhao3 |
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Adress: |
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Abstract:
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The upper crust in the SE Tibetan Plateau is rotating around the eastern Himalayan syntax
clockwise, and the western margin of the Yangtze Craton has been involved in the active tectonics.
However, it is still unclear whether and how the deep crust and upper mantle respond to the plateau
expansion. In this study we present a high-resolution three-dimensional model of P wave velocity
tomography and azimuthal anisotropy in the crust and uppermost mantle beneath the SE Tibetan Plateau
determined using traveltime data recorded by a dense seismic network. Widespread low-velocity zones are
revealed around a high-velocity body in the deep crust and uppermost mantle beneath the southwest
Yangtze Craton, where fast-velocity directions of the azimuthal anisotropy are mostly parallel to the contour
lines of the surface topography and the Moho depth along the plateau margin. These results indicate that
gravitational potential plays an important role in the crustal and uppermost-mantle deformations in the SE
Tibetan Plateau. Meanwhile, the shallow crust may drop down to the deep crust and drive the ductile
deep-crustal material to intrude into the adjacent regions. The extruded crust is trapped in a deep-crustal
corner and obstructed by the surrounding strong blocks. The trapped crustal material may rise up, causing
significant uplift and high heat flow at the surface. |
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Comment: |
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