Vol. 7, Issue 2, Part A (2025)

This study investigates the mineralogical composition and thermal behaviour of subsurface sediment samples collected from Well DND #27, located in the Jaisalmer Basin, Rajasthan. Fourier Transform Infrared (FTIR) spectroscopy was employed to characterize five samples at various depths and track their mineralogical changes across a range of temperatures (Room Temperature to 1000°C). The spectra revealed dominant peaks related to kaolinite, quartz, and calcite, with distinct variations in intensity and position as a function of temperature. Kaolinite dehydroxylation, calcite decarbonation, and quartz stability were tracked through diagnostic vibrational modes. The study demonstrates the significance of FTIR in thermal maturity evaluation and mineral phase identification in sedimentary basins.