TECTONIC CLASSIFICATION OF DHARWAR CRATON, INDIA.BASED ON INVERSION OF REGIONAL BOUGUER GRAVITY.

Regional Bouguergravity data along eleven traverse (73°30' E to 78° 30' E and latitude 12° N to 17°N) across the Dharwar craton data have been analyzed to estimate the deeper crustal configurations. The tectonic differentiation was elucidated on a four layered earth model, constituted a Peneinsular gneisses, Upper and Deeper crustal and Moho layers. Four deep seated faults extending down to Moho were inferred. Running west to east, the First (FI) western part, the second fault F-II corresponds to Bababudan – Nallurshear , the third fault F-III runs along the western margin of closepet batholith and last fourth fault F-IV lies eastern part of the study area. These faults suggest a modified Tectonic classification of the Dharwar Craton we here inferred a Western Dharwar Craton (WDC) bounded it west FII fault (Bababudan Fault) and Eastern Dharwar Craton block east of the FIII fault (EDC), with an Intervening block (IB) in between FII and FIII. The Chitradurga thrust fault (CT), hitherto believe to divide the Dharwar Craton into the two fold classification that is EDC, WDC is inferred to extent only the Gneissic basement rather than being deep seated. The crustal thickness of the each of the tectonic blocks indentified view, west of fault FI, FI- FII, FII - FIII, FIII - FIV and East of FIV depth ranges varies from 32.98- 38.3 Km, 34.71-39 Km, 34.21-35.86 Km, 34.77-38.74 Km and 33.11-38 Km, respectively the average crustal thickness for the West Dharwar Craton (WDC) is 39. Km, Intervening block 34.5 Km and Eastern Dharwar Craton (EDC) 37.Km the crustal thickness beneath the Chitradurga fault (CT) which lies middle of Intervening block is about 34 Km.