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Prabhakar, K. N.
- Evolution of Southern Part of Indian East Coast Basins
Authors
1 KDMIPE, ONGC, Dehradun, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 41, No 3 (1993), Pagination: 215-230Abstract
Regional study of subsurface data of sedimentary basins on the East coast of India to the south of 18° North latitude has led to an appreciation of tectonic styles and sedimentation histories of Krishna-Godavari, Pennar Palar, and Cauvery basins. Tectonics and evolutionary history is understood through three distinct episodes of evolution viz. 'lnterier Fracture', 'Pull Apart' and 'Shelf Sag/Tilt'. These episodes being a part of structural development of passive margins are complicated by phase overlap and shear tcetonics associated with differential movements during the long flight of the Indian sub-plate. The block movements along the major planes of weakness has generated different sub-basins separated by ridges both in Krishna-Godavari and Cauvery basins.These sedimentary basins have 3-8 kms, of sediments. Punctuated with major unconformities they range in age from Proterozoic to Recent. In the outcrops present on the western margin of the basins the stratigraphic record is less complete when compared with subsurface stratigraphic succession. The presence of subsurface Gondwana sediments has been confirmed into Krishna-Godavari basin. The metasediments present above basement both in Krishna-Godavariand the Pennar basins are suggested to be equivalents of Pakhals/Cuddapahs.
Keywords
East Coast Basin Evolution, Krishna-Godavari, Pennar-Palar, Cauvery.- Structural Styles and Role of Basement Configuration in Hydrocarbon Accumulation Patterns: Cauvery Basin, India
Authors
1 KDMIPE, ONGC, Dehra Dun, IN
2 ONGC, Madras, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 46, No 1 (1995), Pagination: 53-63Abstract
An integrated analysis of basement map and fault patterns has revealed that the Cauvery basin came into existence in a tensional regime which existed during the taphrogenic fragmentation of eastern Gondwanaland (Late Jurassic-Early Cretaceous). The main trend of tectonic elements is NE-SW and it changes to NNE-SSW towards southern part of the basin. This change of trend is attributed to post-rift kinematics associated with counterclockwise movement of the Sri Lankan massif away from the Indian craton. The orthogonal trends which form transfer zones are responsible for conservation of regional extensional strain.
It is observed that there is a good correlation between hydrocarbon occurences, transfer zones and fault sets. Synthesis of tectonic, geochemical and lithostratigraphic data has led to better understanding of the role of Basement Configuration in hydrocarbon accumulation patterns.