Receiver functions obtained at INDEPTH III stations located near the Bangong-Nujiang suture in central Tibet display a weak Moho signal and strong P to S conversions within the first 5 s that vary systematically with back-azimuth. A single station with representative azimuthal variations located at the sharp onset of strong SKS splitting, is modeled for both dipping layers and seismic anisotropy by using a global minimization technique. Inversion results indicate strong anisotropy (>10%) near the surface and in the middle crust separated by a south-dipping (∼25°) layer, possibly related to the earlier phase of crustal shortening. Near-surface anisotropy has a fabric dipping steeply southward and trending WNW-ESE that correlates with the suture and younger strike-slip faults. In contrast, midcrustal anisotropy occurs in a low-velocity zone and has a fabric dipping gently (∼18°) northward that might be related to a well-developed near-horizontal rock fabric induced by crustal flow.
- 7205 Seismology: Continental crust (1242)
- 7260 Seismology: Theory and modeling
- 8102 Tectonophysics: Continental contractional orogenic belts
- 8159 Tectonophysics: Rheology - Crust and lithosphere
- 9320 Information Related to Geographic Region: Asia
ASJC Scopus subject areas
- General Earth and Planetary Sciences