Investigation of rare earth element potential in granitic rocks of Sri Lanka special reference to Thonigala granite

Abstract

Rare earth elements include lanthanide series elements plus Sc and Y. These 17 elements are characterised by the European Union (EU) as critical raw materials with significant supply risk due to their broad of emerging technological applications. Due to this ever-increasing demand for rare earth element (REE) related products, new REE-bearing mineral deposits need to be identified and evaluated for the purpose of filling the supply scarcity in the world. Therefore, this research is focused on investigating REE potential in granitic rocks of Sri Lanka, with special reference to Thonigala granitic intrusions. Thonigala granite is enriched with REEs, relatively with high light REE (LREE) concentration. In the rock samples, the average total rare earth element (TREE), LREE, and heavy REE (HREE) concentrations were 328, 285, and 43.1 mg/kg, respectively. The corresponding sediment values were 619, 472, 147 mg/kg, respectively. The presence of REEs in both insitu rock and sediment samples indicated that significant weathering and erosion occurred in the area. Therefore, this research provides insights into REE potential in granitic rocks of Sri Lanka, focusing on Thonigala granite. More geochemical analysis followed by mineralogical and compositional analysis needs to be carried out for future benefit.