2023/11/20 by Getachew, Hailu, Tamiru, Fekadu
#2D model #Anomalies #Chargeability #Gold Mineralization #Resistivity
paper · doi:10.20372/star.v12i1.03
The occurrence of gold has been known in the western green stone belts of Ethiopia, which comprise large areas in western Oromia, Ethiopia. Gold has mainly been extracted from placer deposits and, to a lesser extent, from primary free gold mineralization. The purpose of this study was to investigate possible gold mineralization and to delineate mineralized zones using induced polarisation and magnetic methods in the case of the Adere green stone belt in Nejo district. Induced polarisation and magnetic methods were carried out along thirteen profiles to identify the gold deposit in the area. The integrated survey results showed anomalous zones of gold mineralization area with medium to high chargeability and high resistivity correlated to alteration zones. High resistivity, which was correlated with medium chargeability responses, may indicate areas of greater silicification, and hence, it is a promising zone for gold mineralization. The chargeability anomalies are caused by sulphide manifestations that indicate prospective areas for gold deposits and are mainly associated with metallic sulphide mineralization. The different trending features are indicated on the analytical signal, first the vertical derivative and then the tilt derivative maps. It reveals high contact zones at shallow depths. The quartz veins are hosted mainly in migmatites and were closely associated with gold mineralization. Generally, high chargeability features are described on all line sections. These zones could be due to disseminated sulphide mineralization in silicified formations, which could be related to economic minerals from gold occurrences. Inverted chargeability and resistivity sections showed high chargeability anomalies that extended beyond 60 m.