Origin of sediment gases in Gulf of Kutch using molecular and isotopic studies

Mesozoic sediments world over are known to have copious amount of oil and gas reserves. Gulf of Kutch on the northern part of west coast of India is a unique basin where the basaltic flows (erupted during Cretaceous) separate the Tertiary from the Mesozoic sediments. This volcanic activity may have acted as a catalyst in hydrocarbon generation. Gravity coring of sediments for surface geochemical prospecting studies applying gas chromatography and carbon isotopic studies have been used to assess the type of hydrocarbon gases present in the sediments. Gas chromatographic measurements indicate the generation of light gaseous hydrocarbons, C1 and ∑C2+ in the range of 36 to 475 ppb and 1 to 1449 ppb, respectively. The carbon isotopic signatures (δC13 CH4 in the range of – 37.7 to – 44.0‰ PDB) and elevated wet gas components suggest thermogenic origin for the gases resident in Gulf of Kutch sediments. Autoliths as samples of kimberlite magma M. PATTERSON*, D. FRANCIS AND T. MCCANDLESS Earth & Planetary Science, McGill University, 3450 University Street, Montreal, Quebec, H3A 2A7 (*correspondence: bodhi123@eps.mcgill.ca) Stornoway Diamond Corporation, Suite #800 625 Howe St.Vancouver, B.C, Canada, V6C 2T6