Evolution of the Mesozoic Sedimentary Basins on the East Coast of India

Abstract

The stratigraphy, structure, and tectonics of the Cauvery, Godavari-Krishna, Palar, and Mahanadi Basins located on the east coast of India are considered on the basis of up-to-date surface and subsurface data with particular reference to their evolution during the Mesozoic Era.The sediments exposed in the respective basins are limited to their western and northern borders and represent a relatively smaller stratigraphic interval as compared to the sequence known to be present in the subsurface.Each of these basins is bordered to the west by down-to-the-basin faults. The structural style and recognisable regional trends of the respective basins parallel those of the Eastern Ghats which were largely responsible for their evolution during the Jurassic period. The basin morphology during Late Jurassic comprised horsts and grabens formed due to tensional forces leading to basin subsidence with localised uplifts. The close of the Mesozoic was marked by a regional easterly regression and basinal tilt and an almost complete cessation of horst and graben development and the formation of an essentially monoclinal post-Mesozoic sedimentary cover.A close similarity between the Mesozoic sedimentary basins on the east coast of India and those on the west coast of Australia is marked inasmuch as their tectonic setting, structural style, lithologic suites and faunal and palynological assemblages are concerned. The study broadly indicates that during the Late Jurassic-Early Cretaceous period the basins on the east coast of India were bordered by land masses similar to those postulated to the west of the West Australian basins.

Tectonics of the Indonesian region

“…The geology of the narrow basins that extend onshore is described by Sastri, Sinha, Singh, and Murti (1973), Sastri, Raju, Sinha, and Venkatachala (1974), and Sastri, Raju, Sinha, Venkatachala and Banerji (1977), The known sedimentary record begins later than does that of western Australia: the initial rift may have developed within what is now the Australian side, the final rift developing subsequent ly farther west, leaving the partially filled older basins mostly with Australia. The Cauvery Basin, between lat 9° and 12° N., at about long 80° E., was initiated with Upper Jurassic deposition of clastic sediments derived from the east.…”

The Effect of Thin High Velocity Layers on Seismic Refraction Data: An Example from Mahanadi Basin, India

“…The Eastern Ghat was largely responsible for its evolution during the Jurassic period and limited these basins on the west by basin-penetrating faults. Horsts and grabens, leading to subsidence accompanied by local uplifts, were formed in these basins due to tensional forces during the late Jurassic (SASTRI et al, 1974). Late Carboniferous to Triassic sedimentation in these Palaeozoic rift grabens is fluvial and continental in nature.…”

Basement configuration of KG offshore basin from magnetic anomalies

“…Of the three basins, the Krishna-Godavari (K-G) is a prominent petroliferous basin extending over an area of 28,000 km 2 on land, 24,000 km 2 in 'shallow' (up to 400 m) waters and 18,000 km 2 in deep waters (up to 2000 m) (Sastri et al 1973(Sastri et al , 1974Shenai and Rao 1982;Kumar 1983;Venkateswarlu et al 1992a, b;Murthy et al 1995).…”