New Data of Sedimentology and Geochemistry of Paleogene-lower Neogene Strata in the South Caspian Basin

The Bengal basin is located between Latitudes 25°-20°30’ and Longitude 87°30’ – 90° 30’ in eastern part of India. The formation of the Bengal basin was initiated during Middle-Upper Cretaceous time. Soil samples were collected from the depth of 2.5 to 4 meter and analysed for light hydrocarbon using gas chromatography(GC). Based on GC data samples shows that the methane is present in normal to low concentrations; ethane and propane are very low in concentrations. Selected samples were analyzed for the determination of carbon isotopic composition of 13C1 (methane), 13C2 (ethane) and 13C3 (propane) using GC-C-IRMS. The carbon isotope values for methane (13C1) vary between –30.1‰ and –21.86 ‰ (PDB). The microbial studies were carried out on 384 soils samples. The counts of propane oxidizing bacteria ranges from 0 to 3.052 X 105 CFU/gm of soil sample and standard deviation ()71345 cfu/gm. Based on adsorbed soil gas, carbon isotopes and microbial studies on the soil samples for Bengal Basin area of Radha, Kolkata, Bardhaman show anomalous zone for hydrocarbon and suggest exploration of these blocks using other geophysical tools