Study of geo-chemical environment in organic rich subsurface sediments of Jaisalmer petroliferous basin of Rajasthan, India, using Moessbauer spectroscopy

A 57Fe Moessbauer Spectroscopic study was carried out on brown red coloured samples collected from different depth intervals of two wells (LNR-1 and DND-1) of Jaisalmer petroliferous basin, India. All these samples show a sextet corresponding to hematite along with two quadrupole doublets one correspond to iron in siderite and other correspond to Fe2+in clay minerals. Relative presence of hematite is seem to be correlated with nature of gaseous hydrocarbon discovered in this basin. Our earlier studies also pointed out such correlation between redox environment and presence/absence of hydrocarbon in a basin. We suggest that such correlation is not surprising because rate of sedimentation determines both hydrocarbon prospecting and redox environment in the sediments.