Crustal structure of the northern part of the Proterozoic Cuddapah basin of India from deep seismic soundings and gravity data

Geochemistry of the Palaeoproterozoic quartzites of Lower Cuddapah Supergroup, South India: Implications for the palaeoweathering, provenance, and crustal evolution

“…The Indian Shield preserves thick sequences of Proterozoic sedimentary rocks in number of basins including the Vindhyan, Indravati, Bhima‐Kaladgi, Khariar, Pranhita–Godavari, Chhattisgarh, and Cuddapah basins (Ramakrishnan & Vaidyanadhan, ). Among these, the Cuddapah Basin (CB) represents the longest duration (~1.1 Ga) of depositional history (2.0–0.9 Ga; Collins et al, ), which attains a maximum thickness of about ~4 km on its eastern side (Chandrakala, Mall, Dipankar, & Pandey, ; Kaila et al, ). The sedimentation in lower Cuddapah Basin was initiated with the deposition of Papaghani Group (Gulcheru Formation) which rests unconformably over Neoarchaean graniotoids of Eastern Dharwar Craton as well as Archaean greenstone belts (Dasgupta & Biswas, ; G.S.I., ; Nagaraja Rao et al, ).…”

Eastern Ghats Mobile Belt

“…This Terrain boundary shear zone or thrust defines the border between the Archaean rocks (schist/gneiss) of the eastern margin of the Craton and Proterozoic granulites on the western margin of the Mobile belt. The seismic profile along Alampur-Koniki revealed a major eastern dipping thrust (Kaila et al, 1987). The greater crustal thickness westward underneath near Cuddapah basin, compared to the eastern margin, is the consequence of this upthrusting (Kaila et al, loc.…”

Proterozoic platform sequences of Peninsular India: Implications towards basin evolution and supercontinent assembly

“…The eastern margin of the basin is demarcated by a thrust contact along which the metamorphics of the EGMB are brought over it. The Cuddapah basin has been investigated by various geophysical techniques including deep seismic sounding (DSS) (Kaila et al, 1979(Kaila et al, , 1987, seismic tomography (Gupta et al, 2003), gravity (Verma and Satyanarayana, 1990;Rambabu;Singh and Mishra, 2002), aeromagnetic (Babu , ground-magnetic (Kailasam, 1976) and magnetotelluric (Naganjaneyulu and Harinarayana, 2004) methods. These studies indicate presence of: (a) a 10-11 km thick sedimentary pile over a 40 km thick crust in the eastern part of the basin; (b) step faults in the basement; (c) a mafic-ultramafic lopolith at a shallow depth under the south western part of the basin where mafic sills and volcanics are exposed, and (d) an easterly dipping thrust fault at the eastern margin where high-density lower crust of the EGMB is upthrusted.…”