Gamma-ray protection capacity evaluation and satellite data based mapping for the limestone, charnockite, and gneiss rocks in the Sirugudi taluk of the Dindigul district, India

The remote sensing techniques for investigation and mapping of mineral resources along with the lithological variations have become a leading and optimistic way in recent years. Sirugudi taluk of Dindigul district, Tamil Nadu, is identified with many quarries of limestone and charnockite that have economic importance since that is used in the cement and construction industry. The present study validates the radiation shielding properties of limestone, charnockite, and gneiss rock and the mapping through remote sensing techniques. Several images processing techniques were performed using the Advanced Spaceborne Thermal Emission and Reflection Radiometer data to delineate the boundaries of lithology at Sirugudi. The laboratory-based reflectance spectra obtained for the limestone, charnockite, and gneiss sample in the range of 350 nm-2500 nm shows a remarkable correlation with the significant oxides of the samples. The radiation shielding performance for the present rocks was investigated using the Monte Carlo simulation and the theoretical online program XCOM. The three investigated rock types' linear attenuation coefficient (mu) values are at their maximum at low energies, and the mu rapidly decreases as energy increases in the low energy range. For gneiss, the mu decreases from 32.484 cm(-1) to 4.731 cm(-1) between 0.015 and 0.030 MeV. At all investigated energies, the mu values follow the order of Charnockite > Gneiss > Limestone. Based on the simulated linear attenuation coefficient values, the half-value layer, radiation protection efficiency, and the thickness equivalent were estimated. The estimated results demonstrated that thinner rock thicknesses are needed to shield the incoming photons at lower energies. The half-value thicknesses are 0.021, 0.026, and 0.018 cm for Gneiss, Limestone, and Charnockite at 15 keV.

Automated summary

This study validates the radiation shielding properties of limestone, charnockite, and gneiss rock through remote sensing techniques, reflecting laboratory-based reflectance spectra and Monte Carlo simulation. The results show significant correlations between reflectance spectra and oxides, and reveal the order of radiation shielding effectiveness of the three rock types.