Radiometric studies for monazite along the coastal region of west Godavari, east coast of India

Abstract

The study revealed the presence of monazite in detectable proportions in the coastal black sand concentrates between Mailavanilanka and Biyyaputhippa, south of the Vasishta Godavari confluence. Radioactivity was proportional to the average monazite content and also to heavy mineral percentage of the samples. Optical study of the black sand concentrates revealed the presence of magnetite and ilmenite (opaques), garnet, amphibole, pyroxenes, kyanite, sillimanite, epidote, monazite, zircon, staurolite, tourmaline, rutile and sphene. Since zircon is not radioactive, monazite is the only radioactive mineral and hence the radioactivity is indicative of relative proportions of monazite in the study area. Textural analysis of the samples was also made to know the depositional environments. All the sand samples (beach, river and dune) were fine grained, well sorted and leptokurtic. The beach samples were negatively skewed while the dune and river samples were positively skewed.