Economic and Environmental Geology (자원환경지질)

The Korean Society of Economic and Environmental Geology (대한자원환경지질학회)
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SWIR Application for the Identification of High-Grade Limestones from the Upper Pungchon Formation

풍촌층 상부 층준의 고품위 석회석 동정을 위한 SWIR 적용

  • Kim, Yong-Hwi (Department of Earth and Environmental Sciences, Korea University) ;
  • Kim, Gyoo Bo (Department of Earth and Environmental Sciences, Korea University) ;
  • Choi, Seon-Gyu (Department of Earth and Environmental Sciences, Korea University) ;
  • Kim, Chang Seong (Department of Earth and Environmental Sciences, Korea University)
  • 김용휘 (고려대학교 지구환경과학과) ;
  • 김규보 (고려대학교 지구환경과학과) ;
  • 최선규 (고려대학교 지구환경과학과) ;
  • 김창성 (고려대학교 지구환경과학과)
  • Received : 2016.08.16
  • Accepted : 2016.10.19
  • Published : 2016.10.28
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Abstract

The mineralogical and geochemical characteristics of diverse carbonate rocks can be investigated by using VNIRSWIR(visible near infrared-short wavelength infrared) spectroscopic analysis as a rapid, nondestructive, and inexpensive tool. Comparing whole rock analysis to VNIR-SWIR spectroscopic analysis, the analytical method was investigated to estimate CaO contents, mud impurity, and whiteness of carbonate rocks involved in high-grade limestones in the field. We classify typical carbonate rocks in the upper Pungchon Formation in high-grade limestone mine area such as the Gangweon, Chungmu and Baegun mine in the Jeongseon area. The results show that powdered specimen has much higher reflectance than cutted specimen between the same sample. Whiteness is highly correlated with reflectance(0.99) for powdered specimen. The absorption of mineral mixtures shifts in position as a result of the mass ratio of calcite and dolomite in the Chungmu mine by changing to 75:25, 50:50, and 25:75. The absorption peak position in carbonate mixtures is highly correlated with CaO contents(0.98~0.99). Based on color system, the carbonate rocks are grouped into (milky) white, light grey, light brown, grey, and dark grey. The absorption peak position shifts from 2340 nm to 2320 nm as CaO contents decrease from 55.86 wt.% to 29.71 wt.%. We confirmed that absorption peak position shifts depending on the amount of Ca, which is bonded to $CO{_3}^{-2}$, Mg, and Fe contents replacing Ca. This result suggests that CaO contents in carbonate rocks can be considered to quantitative analysis in the field by spectroscopic analysis.

정선 지역 고품위 석회석 광산인 강원, 충무 및 백운 광산을 대상으로 풍촌층 상부 층준의 대표적 탄산염암을 구분하고 각 유형의 전암 분석 및 VNIR-SWIR(visible near infrared-short wavelength infrared) 분광분석을 실시하여, 현장에서 고품위 석회석의 CaO 함량, 이질 불순물 및 백색도를 평가할 수 있는 분석법을 제시하였다. 동일 시료에서 분말 시료의 분광 반사도는 절단 시편에 비하여 매우 높은 분광 반사도를 보였고, 탄산염암의 분말 시료는 백색도와 분광 반사도가 0.99의 매우 높은 상관관계를 보이고 있다. 전암 분석에서 확인된 충무광산의 방해석과 백운석 분말 시료를 75:25, 50:50, 25:75 질량비로 혼합하여 각각 스펙트럼의 변화를 확인하고, 탄산염암의 CaO 함량과 흡수파장을 비교한 결과 0.98~0.99로 매우 높은 상관도를 보이고 있다. 탄산염암의 흡수파장과 화학조성은 2340 nm(55.86 wt.%)에서 2320 nm(29.71 wt.%)로 이는 $CO{_3}^{-2}$ 성분과 결합하고 있는 Ca 함량과 이를 치환하는 Mg 성분 함량의 차이에 따라 흡수 위치가 변화되는 것을 의미하며, 현장에서 분광분석을 통한 탄산염광물의 CaO 함량을 정량적으로 적용할 수 있다.

Keywords

References

  1. AusSpec International Ltd. (2008) Geologically-based spectral analysis guides for mineral exploration( GMEX). AusSpec International Ltd., Sydney, v.2, p.25.
  2. Baissa, R., Labbassi, K., Launeau, P., Gaudin, A. and Ouajhain, B. (2011) Using HySpex SWIR-320 hyperspectral data for the identification and mapping of minerals in hand specimens of carbonate rocks from the Ankloute Formation(Agadir Basin, Western Morocco). Journal of African Earth Sciences, v.61, p.1-9. https://doi.org/10.1016/j.jafrearsci.2011.04.003
  3. Clark, R., King, T.V.V., Klejwa, M., Swayze, G.A. and Vergo, N. (1990) High spectral resolution reflectance spectroscopy of minerals. Journal of Geophysical Research: Solid Earth, v.95, p.12653-12680. https://doi.org/10.1029/JB095iB08p12653
  4. Gaffey, S.J. (1986) Spectral reflectance of carbonate minerals in the visible and near infrared (0.35-2.55 micron): Calcite, aragonite, and dolomite, American Mineralogist. v.71, p.151-162.
  5. Hunt, G.R. (1977) Spectral signatures of particulate minerals in the visible and near infrared. Geophysics, v.42, p.501-513. https://doi.org/10.1190/1.1440721
  6. Je, Y.K. and Lee, E.J. (1987) Exploration and Development of the Taebaek Orebody in the Yeonwha Pb-Zn Mine. Journal of the Korean Institute of Mining Geology, v.20, p.273-288.
  7. Kim, J.H. and Lee, G.M. (2000) Report of detailed survey: the Jeongseon-Yemi area. Korea Resources Corporation, Wonju, p.73.
  8. Klein, C. and Dutrow, B. (2008) Manual of mineral science. 23rd, John Wiley, New York, p.635.
  9. Korea Institute of Geoscience and Mineral Resources (KIGAM) (2012) Demand and supply data of mineral in 2011. Korea Institute of Geoscience and Mineral Resources, Daejeon, p.95-100.
  10. Korea Resource Corporation(KORES) (2015) Limestone, Available on https://www.kores.net/common/pdfPreview.do?fid=mineralPdf&mc_info_seq=3035.
  11. Noh, J.H., Oh, S.J. and Kim, K.J. (2004) Applied-mineralogical Study on the Mineral Facies and Characteristics of Domestic High-Ca Limestone. Journal of the Mineral Society of Korea, v.17, p.339-355.
  12. Noh, J.H. and Oh, S.J. (2005) Hydrothermal Alteration of the Pungchon Limestone and the Formation of High-Ca Limestone. The Geological Society of Korea, v.41, p.175-197.
  13. Ryu, I.C. (2003) Integrated stratigraphy approach for new additional limestone reserves in the Paleozoic Taebacksan Basin, Korea. The Korean Society of Economic and Environmental Geology, v.32, p.59-74.
  14. Sim, M.S. and Lee, Y.I. (2006) Sequence stratigraphy of the Middle Cambrian Daegi Formation (Korea), and its bearing on the regional stratigraphic correlation. Sedimentary Geology, v.191, p.151-169. https://doi.org/10.1016/j.sedgeo.2006.03.016
  15. Yoon, K.H. and Woo, K.S. (2006) Textural and geochemical characteristics of crystalline limestone (high-purity, limestone) in the Daegi Formation, Korea. Journal of the Geological Society of Korea, v.42, p.561-576.
  16. Zaini, N., van der Meer, F. and van der Werff, H. (2012) Effect of grain size and mineral mixing on carbonate absorption features in the SWIR and TIR wavelength regions. Remote Sensing, v.4, p.987-1003. https://doi.org/10.3390/rs4040987