DOI QR코드

DOI QR Code

Application of Spectral Induced Polarization Method for Skarn Metallic Deposits Exploration

스카른 금속광상 탐사를 위한 광대역 유도분극법 적용성

  • Park, Samgyu (Korea Institute of Geoscience and Mineral Resources (KIGAM)) ;
  • Shin, Seung Wook (Korea Institute of Geoscience and Mineral Resources (KIGAM)) ;
  • Son, Jeong-Sul (Korea Institute of Geoscience and Mineral Resources (KIGAM)) ;
  • Cho, Seong-Jun (Korea Institute of Geoscience and Mineral Resources (KIGAM))
  • Received : 2016.09.01
  • Accepted : 2016.09.26
  • Published : 2016.11.30

Abstract

The development of more advanced geophysical exploration techniques is necessary because the orebodies as yet discovered are increasingly changing in characteristics from shallow/high-grade to deep/low-grade. In this work, laboratory measurement of physical properties of rock samples and a field survey and interpretation of spectral induced polarization (SIP) have been conducted in a skarn metallic deposit, Gagok mine. The purpose of this study is that the applicability of SIP in the exploration of skarn metallic deposits is verified by the comprehensive interpretation between SIP characteristics of rocks obtained from the laboratory measurements and inverted survey results from the field data. In order to understand the SIP characteristics of each lithology, the data of eighty nine rock samples utilized in the previous studies were revaluated. The field survey was carried out using frequency of 0.25 Hz along a survey line designed for intersecting lithological boundaries and evaluating mineralized zones. The mineralized rocks were more conductive (low-resistivity) and capacitive (high-chargeability or strong-phase) than other rocks. Thus, SIP can be one of the very useful tools for the mineral exploration of the skarn deposits.

광물자원개발에 있어서 탐사 대상이 천부 내지 고품위 광체에서 심부 또는 저품위 광체로 전환됨에 따라 보다 진보된 탐사 기술 개발이 요구되고 있다. 본 연구에서는 스카른 금속광상의 하나인 가곡광산을 대상으로 정밀 탐사가 가능한 광대역 유도분극(spectral induced polarization; SIP)을 이용한 암석시료의 실내 물성 측정과 현장탐사를 수행했다. 또한 실내 측정에서 획득한 암석의 광대역 유도분극 특성과 현장 탐사자료의 역해석 결과를 종합적으로 해석함으로써 스카른 금속광상에 대한 광대역 유도분극 탐사 적용성을 검토하였다. 암상별 광대역 유도분극 특성을 파악하기 위해 기존 연구에서 사용된 89개 시료들의 자료를 재평가했다. 현장탐사는 암상의 경계와 스카른 광화대를 평가할 수 있도록 측선을 설정하고, 0.25 Hz 주파수 대역의 자료를 획득하고 역산해석을 수행했다. 광석광물을 수반하고 있는 암석과 스카른 광화대는 낮은 전기비저항 구간을 보이며, 충전성이 높고 음의 위상이 나타났다. 따라서 광대역 유도분극 탐사는 스카른 광상의 광화작용 특성을 해석하는데 유용하다는 것을 알 수 있었다.

Keywords

References

  1. Bishop, J. R., and Emerson, D. W., 1999, Geophysical properties of zinc-bearing deposits, Australian Journal of Earth Sciences, 46(3), 311-328. https://doi.org/10.1046/j.1440-0952.1999.00706.x
  2. Choi, S. G., Choi, B. K., Ahn, Y. H., and Kim, T. H., 2009, Reevaluation of genetic environments of zinc-lead deposits to predict hidden skarn orebody, Journal of Economic & Environmental Geology, 42(4), 301-314.
  3. Chough, S. K., Kwon, S. T., Ree, J. H., and Choi, D. K., 2000, Tectonic and sedimentary evolution of the Korean peninsula: a review and new view, Earth-Science Reviews, 52(1), 175-235. https://doi.org/10.1016/S0012-8252(00)00029-5
  4. Min, D. J., Jung, H. K., Park, S., Chon, H. T., and Kwak, N., 2008, A study of feasibility of dipole-dipole electric method to metallic ore-deposit exploration in Korea, Geophysics and Geophysical Exploration, 11(3), 250-262.
  5. Park, S., and Matsui, T., 1998, Basic study on resistivity of rocks; Ganseki hiteiko ni kansuru kisoteki kenkyu, Butsuri Tansa (Geophysical Exploration), 51(3), 201-209.
  6. Pelton, W., Ward, S., Hallof, P., Sill, W., and Nelson, P., 1978, Mineral discrimination and removal of inductive coupling with multifrequency IP, Geophysics, 43(3), 588-609. https://doi.org/10.1190/1.1440839
  7. Shin, S. W., Park, S., and Shin, D. B., 2015, Development of a new equivalent circuit model for spectral induced polarization data analysis of ore samples, Environmental Earth Sciences, 74(7), 5711-5716. https://doi.org/10.1007/s12665-015-4588-z
  8. Shin, S. W., Park, S., and Kim, H., 2013, Physical properties of rocks at the Gagok skarn deposit, Geophysics and Geophysical Exploration, 16(3), 180-189. https://doi.org/10.7582/GGE.2013.16.3.180
  9. Shin, S. W., Park, S., and Shin, D. B., 2014, Spectral induced polarization response charaterization of Pb-Zn ore bodies at the Gagok mine, Geophysics and Geophysical Exploration, 17(4), 247-252. https://doi.org/10.7582/GGE.2014.17.4.247
  10. Telford, W. M., Geldart, L. P., and Sheriff, R. E., 1990, Applied geophysics, Cambridge University Press, 792p.
  11. Yun, S., and Einaudi, M. T., 1982, Zinc-lead skarns of the Yeonhwa-Ulchin District, South Korea, Economic Geology, 77(4), 1013-1032. https://doi.org/10.2113/gsecongeo.77.4.1013