HR: 1340h
AN: T43A-1385    [Abstracts]
TI: Shear-wave structure of the south Indian lithosphere from Rayleigh wave phase velocity measurements
AU: Gaur, V
EM: gaur@cmmacs.ernet.in
AF: Indian Institute of Astrophysics, Koramangala, Bangalore, 560 034 India
AU: Mitra, S
EM: mitra@gg.iitkgp.ernet.in
AF: Dept. of Geology and Geophysics,Indian Institute of Technology, Kharagpur, Kharagpur, 721302 India
AU: * Priestley, K
EM: keith@esc.cam.ac.uk
AF: Bullard Laboratories, Dept. of Earth Sciences, University of Cambridge, Madingley Rise, Madingley Road, Cambridge, CB3 0EZ United Kingdom
AU: Rai, S S
EM: ssrai_ngri@rediffmail.com
AF: National Geophysical Research Institute, Uppal Road, Hyderabad, 500 007 India
AB: Two station fundamental mode Rayleigh wave phase velocity dispersion measurements for the south Indian Shield have been made between 20 and 200 s period. The dispersion curve for southern India is compared with those from other major shield regions. The south Indian Shield phase velocity dispersion matches closely the dispersion curve of the Canadian Shield (CANSD) while the Siberian Shield dispersion curve is much slower than the south Indian curve. The south African Shield phase velocity curve lies close to the south Indian curve at periods below 40 s, but is slower at longer periods. The differences in these phase velocity dispersion data from the different shield regions largely results from differences in the crustal structure between the various shields. The inversion of the south Indian dispersion data yields a 155±10~km thick high velocity upper mantle lid with Sn-velocity of 4.68~km/s, and an 80~km thick LVZ beneath below the high velocity lid.
DE: 8100 TECTONOPHYSICS
DE: 8103 Continental cratons
DE: 8159 Rheology: crust and lithosphere (8031)
DE: 8199 General or miscellaneous
SC: Tectonophysics [T]
MN: Fall Meeting 2005