POTENSI PENGAYAAN TIMAH PRIMER DAN SEKUNDER SERTA UNSUR TANAH JARANG DI DAERAH SIMPANG PESAK, KABUPATEN BELITUNG TIMUR
Enrichment studies for primary and secondary tin and rare earth elements were carried out in the Simpang Pesak area, East Belitung Regency which is located at the coordinates of UTM 823865 - 827977 mE and 9653722 - 9658725 mS. This study was conducted to determine potential areas for primary and secondary tin content and rare earths in plaser deposits and granite source rock. The analysis was carried out on primary data taken directly in the field, in the form of rock samples and plaser sediment samples. Plaser sample analysis was carried out on three grain size fractions, namely fraction # 48 (297-354 μm), fraction # 100 (149 μm) and fraction -100 (<149 μm). Geochemical analysis using X-Ray Fluorescence (XRF) Portable on rock samples and plaser sediment concentrates to be carried out the levels of lead and rare earth elements. Univariate statistical analysis was performed to determine the limit value of elemental anomalies. Grain Counting Analysis (GCA) was also carried out on samples of plaser sediment to see the minerals contained in these deposits. Rare earth elements found in the study area include yttrium, cerium, and lanthanum. High levels of lead are in the southern part and some in the middle of the study area. High grade rare earth elements are well known in the central part of the study area. Tin and rare earth anomalies are enriched in the morphology of river steps with ancient alluvial plaser types. The factors that influence the anomaly area are ordering process, source rock, and morphology. Further exploration started from the west to the southeast towards the north towards the granite hills in the study area.