DOI QR코드

DOI QR Code

A Geochemical Indicator in Exploration for the Kalaymyo Chromitite Deposit, Myanmar

미얀마 깔레이미요 크롬철석광상 탐사의 지구화학적 인자

  • Park, Jung-Woo (School of Earth and Environmental Sciences, Seoul National University) ;
  • Park, Gyuseung (School of Earth and Environmental Sciences, Seoul National University) ;
  • Heo, Chul-Ho (Mineral Resources Development Research Center, Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources) ;
  • Kim, Jihyuk (School of Earth and Environmental Sciences, Seoul National University)
  • 박정우 (서울대학교 자연과학대학 지구환경과학부) ;
  • 박규승 (서울대학교 자연과학대학 지구환경과학부) ;
  • 허철호 (한국지질자원연구원 광물자원연구본부 자원탐사개발연구센터) ;
  • 김지혁 (서울대학교 자연과학대학 지구환경과학부)
  • Received : 2017.11.28
  • Accepted : 2017.12.26
  • Published : 2017.12.28

Abstract

Korea Institute of Geoscience and Mineral Resources and Department of Geological Survey and Mineral Exploration in Myanmar have explored the Kalaymyo chromitite deposit, Myanmar since 2013. It is now necessary to find a geochemical indicator for efficient mineral exploration in the future and building a 3D geological model for this ore deposit. Mantle podiform chromitite is a major type of Cr ore in this region, which is considered to be formed by mantle-melt interaction beneath the mantle-crust boundary of oceanic lithosphere. In this study we measured major element composition of spinels in harzburgite, dunite and chromitite, and examined the hypothesis that spinel Cr#(molar Cr/(Cr+Al)${\times}$100) can be used as a geochemical indicator in exploration for the Kalaymyo chromitite. The results show that there is a clear correlation between spinel Cr# and distribution of chromitite. The spinel Cr# of harzburgite increases with decreasing the distance from the chromitite bodies. The spinel composition is also closely associated with texture and occurrence of spinels. The high Cr# spinels (30-48) are subhedral to euhedral and enclosed by olivine whereas the low Cr# spinels (16-27) are anhedral and commonly associated with pyroxenes. Often the low Cr# spinels show symplectite intergrowths with pyroxenes, indicating their residual nature. These petrological and geochemical results suggest that the high Cr# spinels have resulted from mantle-melt interaction. We suggest that spinel Cr# can be used as a geochemical indicator for Cr ore exploration and as one of critical factors in 3D geological model in the Kalaymyo chromitite deposit.

한국지질자원연구원(KIGAM)과 미얀마 지질조사광물탐사국(DGSE)은 2013년부터 미얀마 깔레이미요지역 크롬광화대에 대한 공동 탐사를 진행하고 있다. 향후 효율적인 광물자원 예측 및 지질모델링을 위해서 지구화학 인자의 도출이 필요하다. 이 지역에 산출하는 크롬광체는 맨틀 고치형 크롬철석암이며 맨틀-용융체 상호반응으로 형성되는 것으로 알려져 있다. 따라서 크롬철석암을 중심으로 산출하는 하즈버가이트에 서로 다른 정도의 맨틀-용융체 상호반응의 결과가 관찰될 것으로 예상된다. 본 연구에서는 깔레이미요 크롬광화대에서 산출하는 암석의 첨정석에 대한 지구화학 분석을 실시하고 첨정석의 조성과 크롬철석암의 공간적 상관관계를 테스트하였다. 결과는 광체의 주변부에서 하즈버가이트의 첨정석 Cr#(molar Cr/(Cr+Al)${\times}$100)가 높은 반면에 광체에서 멀어질수록 Cr#가 낮아지는 경향을 보인다. 첨정석의 산출 양상도 Cr#에 따라서 명확히 구분된다. 높은 Cr#(>30)을 보이는 첨정석은 대부분 자형 또는 반자형이며 감람석에 둘러싸여 산출되는 반면 Cr#가 낮은 첨정석(<25)은 열편상 또는 타형으로 휘석의 경계부에 산출된다. 이 같은 암석학적, 지구화학적 분석결과는 모암인 하즈버가이트와 이를 침투한 용융체의 상호반응의 결과로 해석된다. 깔레이미요 지역의 크롬광체가 렌즈상 더나이트에 포획되어 산출하기 때문에 지금까지는 탐사의 지시 암석으로 더나이트를 활용하였으나 지표에 노출된 더나이트의 분포는 제한적이기 때문에 하즈버가이트 첨정석의 Cr#를 지화학적 지시자로 활용하여 향후 신규 탐사지역의 광화대 탐사 및 3D 지질 모델링에 적용할 수 있을 것이다.

Acknowledgement

Grant : 3D 지질모델링 플랫폼 기반 광물자원 예측 및 채광효율 향상기술 개발

Supported by : 한국지질자원연구원, 미래창조과학부

References

  1. Ahmed, A.H. (2013) Highly depleted harzburgite-dunite- chromitite complexes from the Neoproterozoic ophiolite, south Eastern Desert, Egypt: A possible recycled upper mantle lithosphere. Precambrian Research, v.233, p.173-192. https://doi.org/10.1016/j.precamres.2013.05.001
  2. Arai, S. (1994) Characterization of spinel peridotites by olivine-spinel compositional relationships: Review and interpretation. Chemical Geology, v.113, p.191-204. https://doi.org/10.1016/0009-2541(94)90066-3
  3. Arai, S. and Miura, M. (2016) Formation and modification of chromitites in the mantle. Lithos, v.264, p.277-295. https://doi.org/10.1016/j.lithos.2016.08.039
  4. Arai, S. and Yurimoto, H. (1994) Podiform chromitites of the Tari-Misaka ultramafic complex, southwestern Japan, as mantle-melt interaction products. Economic Geology, v.89, p.1279-1288. https://doi.org/10.2113/gsecongeo.89.6.1279
  5. Heo, C., Chi, S., Kang, I. and Jin, K. (2014) Occurrence characteristics of bophi vum chromite mineralized zone in the northwestern Myanmar. Economic and Environmental Geology, v.47(4), p.351-362. https://doi.org/10.9719/EEG.2014.47.4.351
  6. Dick, H.J. and Bullen, T. (1984) Chromian spinel as a petrogenetic indicator in abyssal and alpine-type peridotites and spatially associated lavas. Contributions to Mineralogy and Petrology, v.86, p.54-76. https://doi.org/10.1007/BF00373711
  7. Dijkstra, A.H., Barth, M.G., Drury, M.R., Mason, P.R. and Vissers, R.L. (2003) Diffuse porous melt flow and melt-rock reaction in the mantle lithosphere at a slow-spreading ridge: A structural petrology and LAICP- MS study of the Othris Peridotite Massif (Greece). Geochemistry, Geophysics, Geosystems. https://doi.org/10.1029/2001GC000278.
  8. Ghosh, B. and Bhatta, K. (2014) Podiform chromitites in lherzolitic mantle rocks (Andaman ophiolite, India): the role of magma/rock interaction and parental melt composition. Bulletin de la Societe Geologique de France, v.185(2), p.123-130. https://doi.org/10.2113/gssgfbull.185.2.123
  9. Ghosh, B., Pal, T., Bhattacharya, A. and Das, D. (2009) Petrogenetic implications of ophiolitic chromite from Rutland Island, Andaman-a boninitic parentage in supra-subduction setting. Mineralogy and Petrology, v.96, p.59. https://doi.org/10.1007/s00710-008-0039-9
  10. Gonzalez-Jimenez, J.M., Griffin, W.L., Proenza, J.A., Gervilla, F., O'Reilly, S.Y., Akbulut, M., Pearson, N.J. and Arai, S. (2014) Chromitites in ophiolites: How, where, when, why? Part II. The crystallization of chromitites. Lithos, v.189, p.140-158. https://doi.org/10.1016/j.lithos.2013.09.008
  11. Hirose, K. and Kawamoto, T. (1995) Hydrous partial melting of lherzolite at 1 GPa: the effect of H2O on the genesis of basaltic magmas, Earth and Palnetary Science Letters, v.133, p.463-473. https://doi.org/10.1016/0012-821X(95)00096-U
  12. Ishii, T. (1992) Petrological studies of peridotites from diapiritick serpentine seamounts in the Izu-Ogasawara- Mariana forearc, Leg., 125. Proc. Ocean Drill. Proc., Scientific Results, v.125, p.445-485.
  13. Jaques, A.L. and Green, D.H. (1980) Anhydrous melting of peridotite at 0-15 kb pressure and the genesis of tholeiitic baslats. Contributions to Mineralogy and Petrology, v.73, p.289-310.
  14. Liu, C.-Z., Chung, S.-L., Wu, F.-Y., Zhang, C., Xu, Y., Wang, J.-G., Chen, Y. and Guo, S. (2016a) Tethyan suturing in Southeast Asia: Zircon U-Pb and Hf-O isotopic constraints from Myanmar ophiolites. Geology, v.44, p.311-314. https://doi.org/10.1130/G37342.1
  15. Liu, C. Z., Zhang, C., Xu, Y., Wang, J. G., Chen, Y., Guo, S., ... & Sein, K. (2016b). Petrology and geochemistry of mantle peridotites from the Kalaymyo and Myitkyina ophiolites (Myanmar): Implications for tectonic settings. Lithos, v.264. p.495-508. https://doi.org/10.1016/j.lithos.2016.09.013
  16. Malitch, K.N., Belousova, E.A., Griffin, W.L., Badanina, I.Y., Knauf, V.V., O'Reilly, S.Y. and Pearson, N.J. (In Press). Laurite and zircon from the Finero chromitites (Italy): New insights into evolution of the subcontinental mantle. Ore Geology Reviews.
  17. Mitchell, A. (1981) Phanerozoic plate boundaries in mainland SE Asia, the Himalayas and Tibet. Journal of the Geological Society, v.138, p.109-122. https://doi.org/10.1144/gsjgs.138.2.0109
  18. Moghadam, H.S., Khedr, M.Z., Arai, S., Stern, R.J., Ghorbani, G., Tamura, A. and Ottley, C.J. (2015) Arcrelated harzburgite-dunite-chromitite complexes in the mantle section of the Sabzevar ophiolite, Iran: a model for formation of podiform chromitites. Gondwana Research, v.27, p.575-593. https://doi.org/10.1016/j.gr.2013.09.007
  19. Ningthoujam, P., Dubey, C., Guillot, S., Fagion, A.-S. and Shukla, D. (2012) Origin and serpentinization of ultramafic rocks of Manipur Ophiolite Complex in the Indo-Myanmar subduction zone, Northeast India. Journal of Asian Earth Sciences, v.50, p.128-140. https://doi.org/10.1016/j.jseaes.2012.01.004
  20. Niu, X., Liu, F., Yang, J., Dilek, Y., Xu, Z. and Sein, K. (2017) Mineralogy, geochemistry, and melt evolution of the Kalaymyo peridotite massif in the Indo-Myanmar Ranges (western Myanmar), and tectonic implications. Lithosphere, DOI: https://doi.org/10.1130/L589.1
  21. Pal, T., Bhattacharya, A., Nagendran, G., Yanthan, N., Singh, R. and Raghumani, N. (2014) Petrogenesis of chromites from the Manipur ophiolite belt, NE India: evidence for a supra-subduction zone setting prior to Indo-Myanmar collision. Mineralogy and Petrology, v.108, p.713-726. https://doi.org/10.1007/s00710-014-0320-z
  22. Parkinson, I.J. and Pearce, J.A. (1998) Peridotites from the Izu-Bonin-Mariana forearc (ODP Leg 125): evidence for mantle melting and melt-mantle interaction in a supra-subduction zone setting. Journal of Petrology, v.39, p.1577-1618. https://doi.org/10.1093/petroj/39.9.1577
  23. Pearce, J.A., Barker, P., Edwards, S., Parkinson, I. and Leat, P. (2000) Geochemistry and tectonic significance of peridotites from the South Sandwich arc- basin system, South Atlantic. Contributions to Mineralogy and Petrology, v.139, p.36-53. https://doi.org/10.1007/s004100050572
  24. Singh, A.K. (2013) Petrology and geochemistry of Abyssal Peridotites from the Manipur Ophiolite Complex, Indo-Myanmar Orogenic Belt, Northeast India: Implication for melt generation in mid-oceanic ridge environment. Journal of Asian Earth Sciences, v.66, p.258-276. https://doi.org/10.1016/j.jseaes.2013.02.004
  25. Yang, T.N., Hou, Z.Q., Wang, Y., Zhang, H.R. and Wang, Z.L. (2012) Late Paleozoic to Early Mesozoic tectonic evolution of northeast Tibet: Evidence from the Triassic composite western Jinsha-Garze-Litang suture. Tectonics, v.31(4) 10.1029/2011TC003044
  26. Zhou, M.-F., Robinson, P. and Bai, W. (1994) Formation of podiform chromitites by melt/rock interaction in the upper mantle. Mineralium Deposita, v.29, p.98-101.
  27. Zhou, M.-F., Robinson, P.T., Malpas, J. and Li, Z. (1996) Podiform chromitites in the Luobusa ophiolite (southern Tibet): Implications for melt-rock interaction and chromite segregation in the upper mantle. Journal of Petrology, v.37, p.3-21. https://doi.org/10.1093/petrology/37.1.3
  28. Zhou, M.F. and Robinson, P.T. (1997) Origin and tectonic environment of podiform chromite deposits. Econ Geol Bull Soc, v.92, p.259-262. https://doi.org/10.2113/gsecongeo.92.2.259