ALLUVIAL TIN DEPOSIT MODELING IN FORMER ARTISANAL MINES AREA AT BANGKA ISLAND USING A COMBINATION OF GROUND PENETRATING RADAR DATA AND BOREHOLE DATA

• Main Author: VILIARSO SERAN (NIM : 22116305), GUNTAN
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/27599
• Institution: Institut Teknologi Bandung

Field investigations have been conducted in Bangka Island on three different locations aimed to map subsurface conditions and the distribution of alluvial tin deposits at former artisanal mine sites. A combination of the Ground Penetrating Radar (GPR) and Induced Polarization (IP) methods were performed to produce a deposit model. GPR offered high-resolution imaging capabilities and effectively for a wide area. A former borehole data used to support an interpretation of each radargram. The alluvial layer was divided into two main layers, i.e sandstone, and claystone. Each former borehole data passed by GPR line was plotted and tied to radargram interpretation. Withdrawing bedrock boundaries follow the amplitude reflector pattern in points which interpolated using point kriging. The result of the bedrock model from borehole data and radargram are compared to identify the pattern bedrock’s change. The interpretation of the bedrock pattern to discover the bedrock’s change pattern which refers to the existence of the layer which containing tin and is the parameter for validation drilling. A combination of the former borehole as primary data and radargram interpretation as secondary data was carried out using Sequential Gaussian Co-Simulation (SGCS). This method provides realization based on a combination of primary and secondary data to produce recent characteristics. SGCS results are made in the distribution of minimum, quartile 1 (q1) dan mean values afterward each model is generated and validated. Quartile 1 value data distribution provides a very strong correlation with validation data, so it becomes a reliable and optimum bedrock model. Estimation of material volume (tailing) of each block is 344.000 m3 , 718.000 m3 and 1.011.000 m 3 which are influenced by depth dan bedrock model.