Perbandingan Antara Metode Poligon, Inverse Distance Weighting, Dan Ordinary Kriging Pada Estimasi Sumberdaya Timah Aluvial, Dan Analisis Sebaran Endapannya

Abstract

Bangka Island is one of the many regions in Indonesia that has a lot of mineral resources potential. One of them is tin deposit. The distribution of tin deposit in Bangka Island is a continuation of the Tin Mayor South East Asian Tin Belt. Tin deposits are the main commodity in the exploration of metal mineral deposits on Bangka Island, which makes Indonesia one of the largest tin producing countries in the world. One of the tin ore mining companies in Bangka Belitung is PT Timah Tbk which is exploring and estimating this mineral resource for estimation of its reserves. This study aims to determine the amount of alluvial tin resources and to analyze the distribution of alluvial tin by considering the genesis of alluvial tin deposits in ancient rivers. In this study, resource estimation was carried out using polygon methods, inverse distance weighting, and ordinary kriging in order to determine the appropriate method based on geological conditions, genesis deposit, and mineralization of the estimated deposits. Based on the estimation results of the three resources class categories (measured, indicated, and inferred), by the polygon method, the total alluvial tin deposit resource is 8,732 tonnes, by the inverse distance weighting method is 8,627 tonnes, and by the ordinary kriging method is 8,752 tonnes. The distribution of tin at the study area is mostly concentrated on the ridge (upstream) of ancient rivers, the farther from the upstream the concentration of alluvial tin deposits decreases. From the analysis of the amount of resources and the distribution of alluvial tin deposits, the most optimum estimation method is the ordinary kriging method.