HR: 1340h
AN: T23A-1215 [Abstracts]
TI: Lithospheric thickness and mechanical strength of the Indian Shield
AU: * Nair, R
EM: rajeshnair.iitkgp@gmail.com
AF: Indian Institute of Technology, Kharagpur India, Kharagpur, 721302, Kharagpur, Ben
721302, India
AB:
The relative mechanical strength of the Indian subcontinent is determined by a robust coherence method based
on multitaper spectral analysis on overlapping windows of equal size. Representing the elastic properties of the
lithosphere by a transitional coherence wavelength bypasses the need to input rheological variables such as
Young's modulus or Poisson's ratio, which have been shown to vary on other continents. The measurements are
compared in terms of age and find that regions underlain by Proterozoic basement are on average stronger than
regions of Archaean age. This is in stark contrast to the common assumption that mechanical strength should
increase progressively with time. While the transition wavelengths show a good separation between both age
groups and the North and South Indian shields, suggesting they are indeed mechanically distinct, inversions for
absolute effective elastic thickness show a greater overlap.
UR: http://www.facweb.iitkgp.ernet.in/~rajesh/
DE: 1236 Rheology of the lithosphere and mantle (7218, 8160)
DE: 7218 Lithosphere (1236)
DE: 7240 Subduction zones (1207, 1219, 1240)
DE: 8160 Rheology: general (1236, 8032)
SC: Tectonophysics [T]
MN: 2007 Fall Meeting