Delineation of Sulfide Mineralization Zone Based on Geomagnetic and Induced Polarization (IP) Methods in Sangon-II, Kokap, Kulonprogo Districts, Yogyakarta

We used geomagnetic and 2D induced polarization (IP) methods to identify potential gold mineralization zones in the Sangon-II Kolonprogo area, Yogyakarta. Historical geological data indicate that gold mineralization is associated with quartz veins. Magnetic field measurements at 200 points and 8 IP lines were taken in the study area. The results of the Reduction to Pole (RTP) analysis of magnetic data and IP inversion modeling show how the mineralized areas are distributed. Low magnetic anomaly values (<500 nT), medium (500-1000 nT), and high values (>1000 nT) are interpreted as high, medium, and low alteration zones, respectively. By combining resistivity and chargeability values, the IP inversion results show the zoning of mineralized areas in the Sangon-II area. Low resistivity (<50 Ωm) to medium (50-300 Ωm) and high chargeability (>30ms) are zones of saturated water layers, soil on the surface of the weathering of igneous rocks. Resistivity (50-300 Ωm) and medium chargeability (10-30 ms) are alteration zones of silica-clay, argillic, and propylitic. Medium resistivity (50-300) Ωm and high chargeability (>30 ms) are sulfide mineralization zones. High resistivity (> 300 Ωm) and low chargeability (<10 ms) are unaltered volcanic rocks, andesite-rhyodacite, igneous rock, Nanggulan Formation. While resistivity (> 300 Ωm) and high chargeability (> 30 ms) are zones of igneous rock with high metal content as veins. The results of magnetic and IP analysis indicate the presence of a fault with the direction of N350E. This fault controls the alteration process and sulfide mineralization in the Sangon-II area. The distribution of mineralization areas is in the east, extending to the south, around the fault. The results of 3D modeling show that this area is quite promising.