⁵⁷ Fe Mössbauer spectroscopy study was carried out on sedimentary samples collected from different depth interval in Cretaceous sedimentary sequence. These samples were collected from different test wells drilled in Jaisalmer petroliferous basin and also for each well the samples were collected from different depths. The chemical state of iron in Cretaceous sediments has been studied. Iron is found present in pyrite, carbonates and clays. A possible correlation in relative abundance of iron-bearing minerals and the environment of deposition is discussed.