USING GRAIN MINERALOGY TO OBSERVE THE RARE EARTH ELEMENT CONTENT OF ALLUVIAL TIN ON BANGKA ISLAND, INDONESIA
Rare earth elements (REE) are a raw material of high-tech industries that are commonly found in alluvial tin. One area with the potential to contain these elements is the island of Bangka. Geologically, Bangka Island is in the uplifted part of the Sundanese peneplain; it is a continuation of a row of granite rock formations, rich in mineral cassiterite, which have become known as the "Tin Beli". This study aims to investigate the potential for tin alluvial to contain REEs on Bangka Island and to establish an exploration strategy that can be properly developed and managed. Field surveys to collect samples were conducted in June 2018. Drill holes were made using Banka hand drills to take samples at various depths of up to 12 m. Nine drill holes were located in different geological conditions and samples collected at 1 m intervals. with a total of 64 samples created. The samples were prepared in the laboratory by drying and coning-guartering until a suitable sample volume was achieved. Grain counting was the primary analysis used in this Study, the results showed that the major minerals were cassiterite and guartz, centered on the western side of Bangka. Other minerals were found such as zircon,monazite, and xenotime, which indicate the presence of REES in the observed sample.