Analysis of Resistivity Data of Wenner Alpha Configuration on Granite Prospect in 'JT' area, Central Kalimantan, Indonesia

Abstract

The need for igneous rock as a support for development is increasing in line with the rapid development of infrastructure in Kalimantan. Exploration activities are imperative and must be undertaken as soon as possible. Geological and geophysical investigations, including the resistivity method, are conducted as the initial step in exploration activities. In this study, exploration at the ‘JT’ area using the Resistivity method with the Wenner Alpha configuration is supported by drill hole data. There are 17 lines oriented Northwest-Southeast and North-South,  with a line length of 320 meters and 6 points drill hole crossed by a Resistivity path. The processing of the Resistivity data uses the Res2Dinv software and the drill hole by the Strater4  to produce subsurface profiles. The cross-section is correlated with the drill hole profile results using CorelDRAW software. Next is 3D modeling using the Oasis Montaj software. The results obtained from this study are lithology that is interpreted based on resistivity value are soil with resistivity < 20 Ohm-m, under soil layers there are interlocutors between sandstones with claystone with resistivity of 20 - 60 Ohm-m, below that sandstones are originating from Formation Tanjung with a resistivity of 60 - 300 Ohm-m, and below that there is granite with resistivity > 300 Ohm-m. The distribution of granite in this area has very good quality in the northern region as a prospect area. The granite in the southern part has a lower resistivity value, which is thought to be weathered granite