Occurrence and Mineral Characteristics of Au-Ag-Cu-Bi Bearing Quartz Veins in the Estancia de la Virgen area, Guatemala

과테말라 Estancia de la Virgen 지역 금-은-동-비스무스 광화대의 산상과 광물특성

  • Shin, Eui-Cheol (Korea International Cooperation Agency (KOICA)) ;
  • Kim, Soo-Young (Korea INstitute of Geology, Minning and Materials (KIGAM)) ;
  • Hong, Sei-Sun (Korea INstitute of Geology, Minning and Materials (KIGAM)) ;
  • Kim, In-Joon (Korea INstitute of Geology, Minning and Materials (KIGAM))
  • Received : 1998.07.24
  • Accepted : 1998.11.21
  • Published : 1998.12.31

Abstract

The survey was carried out in order to delineate the occurrence of ore deposits and the mineralized characteristics in the Estancia de la Virgen area through the 1:2,000 scaled geological mapping and topographic measuring surveys. Gold-silver mineralization is in the fault block developed between the San Agustin Fault and Cabanas Fault. It is associated with ore bearing quartz veins controlled by the fault structure. The contents of Au and Ag range from traces up to 72 g/t and 180 g/t respectively. According to traversing the outcrops, the quartz veins are traced by 0.5 Km trended to north and south. In those extended part, they continue for 1,000 m intermittently. Gold-silver mineralization could be divided into three stages. In the first stage, pyrite, galena, sphalerite, and chalcopyrite were formed with the primary silver and gold associated with galena and copper sulfides respectively. In the second stage, Cu-Bi-Au-Ag bearing sulfides such as chalcocite, covellite, and linarite are formed and usually deposited on the cataclastic fractures of galena and/or chalcopyrite. In the third stage, both the carbonation of galena and sphalerite and the sulphatization of galena, took place in the surface environment. And then primary silver was carried away off and was deposited on galena and/or copper sulfides during oxidation near the water table. Low partitionings of Fe in sphalerite assist that the minerals were formed at the relatively low temperature, which is coincided with previously reported homogenization temperature of fluid inclusions.

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