Present‐Day Strike‐Slip Faulting and Intracontinental Deformation of North China: Constraints From Improved GPS Observations

Autor: Xinnan Li, William C. Hammond, Ian K. D. Pierce, Jayne M. Bormann, Zhuqi Zhang, Chuanyou Li, Wenjun Zheng, Peizhen Zhang
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Geochemistry, Geophysics, Geosystems, Vol 24, Iss 7, Pp n/a-n/a (2023)
Druh dokumentu: article
ISSN: 1525-2027
DOI: 10.1029/2022GC010781
Popis: Abstract We investigate the present‐day strike‐slip faulting and intracontinental deformation of North China using horizontal GPS velocities and a block modeling strategy. The data demonstrate that the fault slip rates and block rotations in North China can be better constrained using GPS velocities where the influence of groundwater extraction has been reduced by applying median spatial filtering of the velocity field. The modeled senses of motion and slip rates on active faults are generally in good agreement with the geological estimates. The left‐lateral slip rate along the boundary fault of Weihe Graben is apparently lower than the differential motion between the South China Block and Ordos Block. The missing left‐lateral slip is accommodated by the counterclockwise rotation of the Ordos Block. The sinistral slip rate along the eastern segment of the Altyn Tagh‐Haiyuan‐Qinling fault system decreases eastward from ∼1.0 to ∼0 mm/yr, much slower than that expected in the fast eastward extrusion hypothesis. We interpret the systematic counterclockwise rotation of blocks and left/right‐lateral faulting in North China to be driven both by the left‐lateral shear between the South China Block to the south and Yinshan‐Yanshan Block to the north and a push from the Tibetan Plateau on the southwestern margin of the Ordos Block.
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