자원환경지질 (Economic and Environmental Geology)

  • 제50권2호
  • /
  • Pages.85-96
  • /
  • 2017
  • /
  • 1225-7281(pISSN)
  • /
  • 2288-7962(eISSN)
대한자원환경지질학회 (The Korean Society of Economic and Environmental Geology)
권호 표지
DOI QR코드

DOI QR Code

창원시 의창지역 보난자형 금광상 성인 : 반응경로 모델링에 의한 지구화학적 해석

Genesis of Bonanza-style Ores in Uichang Area, Changwon City: Geochemical Interpretation by Reaction Path Modeling

  • 이승한 (부경대학교 지구환경과학과) ;
  • 노상건 (한국지질자원연구원) ;
  • 박맹언 (부경대학교 지구환경과학과)
  • Lee, Seung-han (Department of Earth and Environmental Sciences, Pukyong National University) ;
  • No, Sang-gun (Korea Institute of Geoscience and Mineral Resoures) ;
  • Park, Maeng-Eon (Department of Earth and Environmental Sciences, Pukyong National University)
  • 투고 : 2017.03.28
  • 심사 : 2017.04.28
  • 발행 : 2017.04.28
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

의창지역의 삼정광산과 용장광산의 금광화작용은 보난자(Bonanza)형 금광상의 특성을 나타낸다. 광상은 퇴적암 내의 장석질 사암과 석영맥의 접촉부에서 주로 산출되며, 금과 은을 함유하는 광물은 에렉트럼과 더불어 은황화광물 및 황산염광물로 산출된다. 반면, 광상의 모암이 쳐트질 암석과 안산암인 경우에는 금광화작용이 장석질 사암의 경우보다 미약하게 발달된다. 이 연구에서는 금의 침전 특성을 파악하기 위하여 열수용액과 장석질 사암 및 안산암간의 수치모델링에 의한 다성분 다상계 평형계산을 실시하였다. 모델링에서는 함금은 광물인 에렉트럼 및 수용액상 또는 기상 원소들이 사용되었다. 반응경로 모델링 결과, pH가 증가함에 따라 석영, 녹니석, 견운모, 황동석, 방연석, 황철석, 에렉트럼, 양기석과 장석이 침전되었다. 또한, 에렉트럼은 모암과 광화용액 간의 반응에 의한 급격한 pH 증가와 탈황화작용에 의해 침전되었음을 확인하였다. 금 은비는 용액의 pH 조건이나 아칸다이트와 폴리바사이트와 같은 은황화 광물 침전에 의해 변화되었다. 한편, 안산암과 열수용액과의 반응에서 침전된 광물은 열수용액과 장석질 사암과의 반응에서 침전된 광물과 유사하지만 상대적으로 적은 양의 에렉트럼이 침전되었다. 이러한 연구결과로 미루어 볼 때 의창지역 보난자형 금광화작용의 부광대는 모암 규제에 의해 형성되었다고 판단된다.

Gold mineralization of Samjeong and Yongjang gold mines in Uichang area shows characteristics of Bonanza-type gold deposits. Ores are mainly developed along the contact parts between quartz vein and arkosic sandstone beds(Fe-rich bed) in sedimentary rock. Electrum, silver sulfide and sulfate minerals are mainly in the ores. On the other hand, gold mineralization is less developed in cherty rock and andesitic rock than arkosic sandstone. The study highlights characteristics of gold precipitation in the deposit on the basis of numerical modelling of the reactions between the assumed hydrothermal ore fluids with multicomponent heterogeneous equilibrium calculations. Aqueous species, gases and minerals, containing electrum are included in the calculations. The reaction result between hydrothermal ore fluids and arkosic sandstone show that pH increasing in the ore-forming fluid would trigger precipitation of quartz, chlorite, sericite, chalcopyrite, galena, pyrite, electrum, actinolite and feldspar. The numerical modelling also illustrates the drastic increase of pH and desulfidation lead to precipitation of electrum. Ag/Au ratios in the ore vary with pH conditions and subsequently precipitation of silver-bearing sulfides such as acanthite and polybasite. The modelling of the reaction between andesitic rock and ore-forming fluid shows that mineral assemblages of the case are analogous to ones of the reaction between arkosic sandstone and fluid except the latter has little portion of electrum. The abovementioned modelling results suggest that gold-silver mineralization is bounded by host rocks at the study area.

키워드

참고문헌

  1. Barton, P.B. Jr and Toulmin, P. III (1964) The electrumtarnish method for determination of the fugacity of sulfur in laboratory sulfide systems. Geochim. et Cosmochim. Acta., v.28. p.619-640. https://doi.org/10.1016/0016-7037(64)90082-1
  2. Choi, S.G. and Wee, S.M. (1992) The genetic characteristics of gold and/or silver vein deposits related to chemical composition of electrum in central Korea. Jour. Geol. Soc. Korea, v.28, no.2, p.196-217.
  3. Choi, S.G., Park, M.E. and Choi, S.H. (1994) Chemical variations of electrum from gold and/or silver deposits in the Southeast Korea. Jour. Econ. Environ. Geol., v.27, no.4, p.325-333.
  4. Choi, S.G., Kwon, S.T., Lee, J.H., So, C.S. and Pak, S.J. (2005a) Origin of Mesozoic gold deposits in South Korea. Island Arc., v.14, p.102-114. https://doi.org/10.1111/j.1440-1738.2005.00459.x
  5. Choi, S.G., Ryu, I.C., Pak, S.J., Wee, S.M., Kim, C.S. and Park, M.E. (2005b) Cretaceous epithermal gold-silver mineralization and geodynamic environment, Korea. Ore Geol. Revol., v.26, p.115-135. https://doi.org/10.1016/j.oregeorev.2004.10.005
  6. Choi, Y.K. and Kim, T.Y. (1963) Explanatory text of the geological map of Masan sheet (1:50,000). Geological survey of Korea. 29p.
  7. Drummond, S. and Ohmoto, H. (1985) Chemical evolution and mineral deposition in boiling hydrothermal systems. Econ. Geol., v.80, p.126-127. https://doi.org/10.2113/gsecongeo.80.1.126
  8. Gallagher, D. (1963) Mineral resources of Korea. Issued by mining branch, Industry and mining Div. USOM/ Korea., v.3, p.7-19.
  9. Korea Resources Corp. (1983) Gold report I. 362p.
  10. Korea Resources Corp. (1984) Gold report II. 261p.
  11. Korea Resources Corp. (2004) Detailed geological survey report. 63p.
  12. Kim, J.H. and Kim, J.T. (1963) Explanatory text of the geological map of Masan sheet (1:50,000). Geological survey of Korea. 45p.
  13. Korea Resources Corp. (1973) Economic mineral deposits in Korea vol.5, p.376.
  14. Korea Resources Corp. (1981) Economic mineral deposits in Korea vol.8, p.205-503.
  15. Korea Resources Corp.(KORES) (2011) Distribution map of mineral resources in Korea.
  16. Lee, J.D. (1992) Contact Metamorphism in the Chindong- Masan area of Gyeongsangnamdo. Korea Earth Science Society, v.13, no.4, p.497-509.
  17. Lee, K.Y. (1991) Genetic environments of the Tongyeong gold and silver bearing hydrothermal vein deposit, Korea. Ph.d. thesis, Korea Univ., 139p.
  18. Park, H.I. and Kang, S.J. (1988) Gold and Silver Mineralization of Samhyungje Vein Mugeug Mine. Jour. Korean Inst. Mining Geol., no.3, p.257-268.
  19. Park, M.E. (1992) Geochemical Modeling of Gold-Silver Precipitation in Epithermal System of Uichang Area. Korea Research Foundation report.
  20. Park, M.E. (2001) Genesis and hydrothermal alteration of an anorthosite-hosted gold-silver deposits at Hadong area. National research foundation of Korea, p.34.
  21. Park. M.E., Choi, I.S. and Kim, J.S. (1992) Hydrothermal solution-rhyolite reaction and origin of sericite in the Yukwang mine. Jour. Korean Inst. Mining Geol., v.25, no.3, p.225-232.
  22. Park, M.E., Sung, K.Y. and Laurence, P.J. (2001a) Au-Ag- Te Mineralization by Boiling and Dilution of Meteoric Groundwater in the Tongyeong Epithermal Gold System, Korea: Implications from Reaction Path Modeling. Jour. Econ. Environ. Geol., v.34, no.6, p.507-522.
  23. Park, M.E., Sung, K.Y. and Yun, S.T. (2001b) Gold Deposition by Boiling or Cooling Without Boiling: Genesis of the Sangchon Gold Deposits, Hadong Area, South Korea. Jour. Geoscientific Research in Northeast Asia, v.4, p.139-150.
  24. Park, N.Y. and Chi, J.M. (1963) Geologic map of Jindong-ri. Korea Institute of Geoscience and Mineral Resources.
  25. Reed, M.H. (1982) Calculation of multicomponent chemical equilibria and reaction processes in systems involving minerals, gases and an aqueous phase. Geochim. Cosmochim. Acta, v.46, p.513-528. https://doi.org/10.1016/0016-7037(82)90155-7
  26. Reed, M.H. and Spycher, N.F. (1983) Calculated effects of boiling, cooling and oxidation on precipitation of ore and gangue minerals from hydrothermal solution. Fourth International Symposium on Water-Rock Interaction, Misassa, Japan, 1983, Extended Abstracts, p.485-408.
  27. Reed, M.H. (1984) Geology, wall-rock alteration, and massive sulfide mineralization in al Portion of the West Shasta District, California. Economic Geology, v.79, p.1299-1318. https://doi.org/10.2113/gsecongeo.79.6.1299
  28. Reed, M.H. and Spcher, N.F. (1985) Boiling, cooling and oxidation in epithermal systems: A numerical modelling approach. Geology and Geochemistry of Epithermal Systems, Reviews in Economic Geology, v.2, p.249-272.
  29. Shelton, K.L., So, C.S. and Chang, J.S. (1988) Gold-rich mesothermal vein deposits of the Republic of Korea: Geochemical studies of the Jungwon gold area. Economic Geology, v.83, p.1221-1237. https://doi.org/10.2113/gsecongeo.83.6.1221
  30. Shelton, K.L., So, C.S., Haeussler, T., Chi, S.J. and Lee, K.Y. (1990) Geochemical studies of the Tongyoung gold-silver deposits, Republic of Korea; evidence of meteoric water dominance in a Te-bearing epithermal system. Economic Geology, v.85, no.6, p.1114-1132. https://doi.org/10.2113/gsecongeo.85.6.1114
  31. Shimazaki, H., Lee, M.S., Tsusue, A. and Kaneda, H. (1986) Three epochs of gold mineralization in South Korea. Mining Geol., v.36, p.265-272.
  32. Shin, S.C. and Jin, M.S. (1995) Isotope age map of plutonic rocks in Korea(1:1,000,000. Korea institute of geology, mining and materials.
  33. So, C.S. and Shelton, K.L. (1987) Fluid Inclusion and Stable Isotope Studies of Gold-Si11ver-Bearing Hydrothermal Vein Deposets, Yeoju Mining district, Republic of Korea: Econ. Geol., v.82, p.1309-1318. https://doi.org/10.2113/gsecongeo.82.5.1309
  34. So, C.S., Yun, S.T., Choi, S.H. and Shelton, K.L. (1989) Geochemical studies of hydrothermal gold-silver deposits, Republic of Korea: Youngdong mining district. Mining Geol., v.39, p.9-19.
  35. Son, C.M. (1968) On the Creataceous Igneous Activities in Korea. Jour. Geol. Soc. Korea, v.5, no.4, p.259-267.
  36. Spycher, N.F. and Reed, M.H. (1986) Boiling of geothermal water: Precipitation of base and precious metals, speciation of arsenic and antimony, and the role of gas phase metal transport. Proceeding of the Workshop on Geochemical Modeling, Fallen Leaf Lake, September, 1986, U.C.R.L. Publication (in press, personal communication).
  37. Spycher, N.F. and Reed, M.H. (1989) Evolution of a Broadlands-type epithermal ore fluid along alternative P-T path: implications for the transport and deposition base, precious, and volatile metals. Economic Geology., v.84, p.328-359. https://doi.org/10.2113/gsecongeo.84.2.328
  38. Spycher, N.F. and Reed, M.H. (1991) SOLTHERM data base for program SOLVEQ, MINSOLV, CHILLER, GEOCAL and KCAL(Personal Communication).
  39. Taguchi, S. and Hirowatari, F. (1976) Quantitative electron microanalysis of electrum by Bence and Albee method. J. Min. Soc. Japan, 12, Special Issue, p. 82-85 (In Japanese).
  40. White, D.E. and Heropoulos, C. (1983) Active and fossil hydrothermal convection systems of the Great Basin. Geoth. Res. Council Special Report, 13, p.41-53.
  41. Yoo, B.C., Choi, S.G. and Lee, H.K. (2002) Mode of Occurrence and Chemical Composition of Electrums from the Gubong Gold-Silver Deposits, Republic of Korea. Jour, Econ, Environ, Geol., v.35, no.3, p.191-201.