Application of Polarization Method (IP) to Delineate the Gold Mineralization Zones in Cihonje Areas, Banyumas Regency, Province of Central Java

Abstract

The main problem in metal mineral exploration is determining the deposits at subsurface. This deposit is associated with the surrounding rocks so it is not easy to distinguish. One of the Geophysical methods that can be used for that is the Induced Polarization (IP) method. This method produces two parameters i.e resistivity and chargeability, which very well distinguishes the metal mineral content in rocks. This study, in which the IP method was implemented, was carried out in the Cihonje area, Gumelar Subdistrict, Banyumas Regency, Central Java Province. It aimed to find out the distribution of the gold mineralization zone. The IP data with a total of nine lines were obtained through Junior Syscal 458, using Dipole-dipole configuration, with n=1 to 6 and 20 meters of electrodes spacing. The distribution of gold mineralization areas estimated using by Res2DInv and RockWork15 modeling. An attempt in combining the resistivity and chargeability values was done to identify the anomalous zone boundaries. The results showed that Cihonje area could be grouped into four zones, i.e saturated water layer, alteration, gold mineralization and non-alterated volcanic rock zone. The resistivity and chargeability values are (0-100) Ωm and (0-10) ms, (0-100) Ωm and > 10 ms, > 100 Ωm and > 10 ms, > 100 Ωm and (0-10) ms respectively. The gold mineralization zone is spread into two areas, i.e the western and the eastern area which is separated by the Left Paningkaban Shear Fault.