TINJAUAN GEOLOGI DEPOSIT BIJIH PADA DAERAH KALIREJO, KULON PROGO

Abstract

The Kulon Progo area is included in the West Progo Mountains area which is physiographically a large dome with a relatively flat peak and steep sides. This paper discusses the potential for ore deposits in the Kalirejo (Sangon and Plampang), Kokap, Kulon Progo areas. The process of alteration and mineralization of ore occurs in andesite rocks which are included in the Old Andesite Formation, with the type of hydrothermal alteration that developed in the Sangon and Plampang areas in the form of propylitic zone associated with epidote-chlorite-calcite mineral, zone of argillic associated with illite-kaolin-monmorillonite, phyllic zone associated with quartz-sericite-chlorite as a characteristic mineral and silicified zone characterized by the presence of silica minerals. The ore mineralization is in the form of gold and sulfide groups such as pyrite, chalcopyrite, galena, bornite, covelite, sphalerite, and arsenopyrite and is located in an advanced argillic zone with veins trending southwest-northeast, with a hydrothermal deposit type in the form of low sulfidation epithermal deposits.