Mineralogical exploration for rare earth element potential in Kalutara coastal areas

Abstract

Rare Earth Element (REE) quantity is a main factor that determines the wealth of a country. The main aim of this study is to discover a new REE deposit that can contribute to the Sri Lankan economy. Calido Beach is a coastal region where Kalu-river joins the sea in Kalutara, Sri Lanka. In this study, this coastal region is divided into four divisions as Kalutara North (KN), Kalutara South (KS), Sand Spit (SS) and river delta. Beach sand (n=5) and river sediment (n=30) samples were collected covering all four divisions and analyzed for mineralogy, grain size distribution and microscopic observation for prospecting unconventional Rare Earth Mineral (REM) sources. Analysis for mineralogy of samples via X-ray Diffraction (XRD) test revealed positive availability of REMs such as Monazite (Ce), Monazite (Nd), Xenotime and Bastnasite. According to grain size distribution (GSD) test results, it was found that sediments in delta had a lesser time for sorting before deposition with relevance to beach sand. Nourishment of REMs into the shore by sea waves and other sources (Beruwala placer deposit, offshore sources) increases the amount of REM content in the study area and the minable quality of beach sand as an economically viable REE source.