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Mineralogy and Geochemistry of Minerals from the Jinwon Gold-silver Deposit, Republic of Korea

진원 금-은 광상에서 산출되는 광물들의 산출상태 및 화학조성

  • Yoo, Bong Chul (Mineral Resources Technology Research Department, Convergence Research Center for Development Of Mineral Resources, Korea Institute of Geoscience and Mineral Resources)
  • 유봉철 (한국지질자원연구원 DMR융합연구단 광물자원기술연구팀)
  • Received : 2016.11.09
  • Accepted : 2017.01.02
  • Published : 2016.12.28

Abstract

Jinwon Au-Ag deposit is located in the Uijin gun which is southeast 300 km from Seoul. The deposit area consists of mainly Precambrian Hongjesa granite, which occurs as porphyroblastic texture, medium grain and composed of quartz, feldspar and mica. This deposit consists of four parallel hydrothermal quartz veins that fill NE oriented fractures in Precambrian Hongjesa granite. The grade of quartz veins contain from 3.0 to 21.4 g/t (average 6.4 g/t) gold and from 5.0 to 252.0 g/t (average 117.9 g/t) silver, respectively. They vary from 0.2 m to 0.6 m (average 0.3 m) in thickness and extend to about 200 m in strike length. Quartz veins occur as massive, network, cavity, breccia, crustiform, comb and zonal textures. Wallrock alteration has silicification, sericitization, pyritization and argillitization. The mineralogy of the quartz veins consists of quartz, arsenopyrite, cassiterite, pyrite, sphalerite, chalcopyrite, galena, electrum, tetrahedrite, canfieldite, argentite, Ag-Sb-S mineral, Mn-Fe-O mineral, Pb-O mineral and Pb-P-Cl-O mineral(chloro-pyromorphite). Chemical compositions of minerals from this deposit are as followed; Fe/Fe+Mg of sericite is from 0.32 to 0.71, As content of arsenopyrite ranges from 27.91 to 30.33 atomic %, FeS content of sphalerite range from 9.77 to 16.76 mole %, Ag content of electrum is from 29.42 to 37.41 atomic % and Ag content of tetrahedrite range from 32.17 to 36.53 wt.%, respectively. Baased on mineralogy and chemical compositions of minerals from Jinwon Au-Ag deposit, deposition of minerals was caused by a change in temperature, oxygen fugacity($fO_2$) and sulfur fugacity($fS_2$) from the near neutral hydrothermal fluid evolved by reaction with wallrock.

Acknowledgement

Grant : 태백산 광화대 유망광체 확보를 위한 지질광상조사 및 성인 연구

Supported by : 한국지질자원연구원

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