Open AccessImprints of a Proterozoic tectonothermal anomaly below the 1.1 Ga kimberlitic province of Southwest Cuddapah basin, Dharwar craton (Southern India)
Author(s) -
Mall D. M.,
Pandey O. P.,
Chandrakala K.,
Reddy P. R.
Publication year - 2008
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.2007.03623.x
Subject(s) - geology , dharwar craton , lithosphere , indian shield , crust , anomaly (physics) , proterozoic , underplating , craton , structural basin , geophysics , gravity anomaly , geochemistry , mantle (geology) , shield , petrology , seismology , tectonics , geomorphology , paleontology , physics , condensed matter physics , oil field
SUMMARY A detailed 2‐D modelling of the seismic structure and other geological and geophysical signatures across the Cuddapah basin of the southern Indian shield suggests upwarping of high‐velocity and high‐density layers, which are observed close to the surface below the southwestern part of the basin. This anomalous feature is constrained by (i) a strong gravity high anomaly of about 55 mGal, (ii) a 100 km wide high conductivity anomaly (resistivity < 100 Ω‐m) extending from surface to a minimum depth of 50 km in the mantle lithosphere and (iii) large scale massive intrusive activity. These features are interpreted to be an expression of a thermal anomaly, which may have acted like a plume during the Proterozoic and could well correspond to a 1.1 Ga kimberlitic activity. Below this region, the thin granitic–gneissic crust is underlain by well‐differentiated, high‐velocity layers, possibly due to underplating and densification of much of the crust by extruded magma.