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Shear velocity structure of the laterally heterogeneous crust and uppermost mantle beneath the Indian region
- Source :
- Scopus-Elsevier
- Publication Year :
- 1997
- Publisher :
- Elsevier BV, 1997.
-
Abstract
- The shear velocity structure of the Indian lithosphere is mapped by inverting regionalized Rayleigh wave group velocities in time periods of 15-60 s. The regionalized maps are used to subdivide the Indian plate into several geologic units and determine the variation of velocity with depth in each unit. The Hedgehog Monte Carlo technique is used to obtain the shear wave velocity structure for each geologic unit, revealing distinct velocity variations in the lower crust and uppermost mantle. The Indian shield has a high-velocity (4.4-4.6 km/s) upper mantle which, however, is slower than other shields in the world. The central Indian platform comprised of Proterozoic basins and cratons is marked by a distinct low-velocity (4.0-4.2 km/s) upper mantle. Lower crustal velocities in the Indian lithosphere generally range between 3.8 and 4.0 km/s with the oceanic segments and the sedimentary basins marked by marginally higher and lower velocities, respectively. A remarkable contrast is observed in upper mantle velocities between the northern and eastern convergence fronts of the Indian plate. The South Burma region along the eastern subduction front of the Indian oceanic lithosphere shows significant velocity enhancement in the lower crust and upper mantle. High velocities (approximate to 4.8 km/s) are also observed in the upper mantle beneath the Ninetyeast ridge in the northeastern Indian Ocean.
- Subjects :
- Shear Velocity
Phase-Velocity
Lithosphere
Regionalization
Evolution
Mantle (geology)
Volcanism
Monte Carlo Technique
Oceanic crust
Shear velocity
Petrology
Earth-Surface Processes
geography
geography.geographical_feature_category
Subduction
Plate-Tectonics
Bengal
Crust
Surface-Wave Dispersion
Craton
Rayleigh Wave
Geophysics
Shield
Hotspots
Indian Shield
Geology
Seismology
Rayleigh-Waves
Subjects
Details
- ISSN :
- 00401951
- Volume :
- 277
- Database :
- OpenAIRE
- Journal :
- Tectonophysics
- Accession number :
- edsair.doi.dedup.....4801cfed804e83152bf4bccf68c4f7e5