Multidisciplinary investigations exploring indicators of gas hydrate occurrence in the Krishna–Godavari Basin offshore, east coast of India

Autor: M.V. Ramana, H.M. Joao, M. Kocherla, C. Prakash Babu, J. N. Pattan, A.V. Sathe, S. M. Karisiddaiah, N. H. Khadge, Maria-Judith Gonsalves, A.L. Paropkari, B. Ramalingeswara Rao, D. V. Borole, Pushpendra Kumar, T. Ramprasad, M. Desa, P. Lokabharati, A.K. Sethi
Rok vydání: 2008
Předmět:
Zdroj: Geo-Marine Letters. 29:25-38
ISSN: 1432-1157
0276-0460
DOI: 10.1007/s00367-008-0121-7
Popis: We report some main results of multidisciplinary investigations carried out within the framework of the Indian National Gas Hydrate Program in 2002–2003 in the Krishna–Godavari Basin offshore sector, east coast of India, to explore indicators of likely gas hydrate occurrence suggested by preliminary multi-channel seismic reflection data and estimates of gas hydrate stability zone thickness. Swath bathymetry data reveal new evidence of three distinct geomorphic units representing (1) a delta front incised by several narrow valleys and mass flows, (2) a deep fan in the east and (3) a WNW–ESE-trending sedimentary ridge in the south. Deep-tow digital side-scan sonar, multi-frequency chirp sonar, and sub-bottom profiler records indicate several surface and subsurface gas-escape features with a highly resolved stratification within the upper 50 m sedimentary strata. Multi-channel seismic reflection data show the presence of bottom simulating reflections of continuous to discrete character. Textural analyses of 76 gravity cores indicate that the sediments are mostly silty clay. Geochemical analyses reveal decreasing downcore pore water sulphate (SO42−) concentrations (28.7 to
Databáze: OpenAIRE
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