Geosciences Journal

, 1:202 | Cite as

A review on the origin of micrographic granites (Masanites) in the southern Kyongsang Basin, Korea

  • Jong Ik Lee


The origin of micrographic granites (formerly called Masanites) in the southern Kyongsang Basin is discussed on the basis of the petrological, mineralogical, and geochemical characteristics along with comparisons with experimental references. The micrographic granite in the Masan area occurs as several dikes of minor quantity in a hornblende-biotite granite, whereas those in the Kimhae and Busan areas are gradational to the porphyritic biotite (±hornblende) granites, forming discrete stocks together with the accompanying granites. Geochemical properties of the micrographic granites are largely dependent upon those of the accompanying granites. This suggests that the individual micrographic granites are not independent intrusive bodies. The most important factor for the formation of micrographic intergrowths was probably the degree of undercooling during the decompression under a kinetically driven, nonequilibrium condition. The micrographic intergrowth of quartz was probably formed at moderate degree (at least 100°C) of undercooling from a H2O-saturated magma emplaced into the shallow crustal levels. Common occurrence of miarolitic cavities in the micrographic granites indicates that vapor exsolution would enhance the degree of undercooling of the melt. Chemical compositions of magmas were another important factor for controlling the sequence of liquidus phases. Quartz should have higher liquidus temperature than alkali feldspar under the condition of moderate degree of undercooling. The bulk composition of magmas might not correspond to the eutectic composition, so as to form micrographic intergrowths, given the fact that the composition of the Kimhae micrographic granite is incompatible with any known eutectic one. The spatial distribution of the micrographic granites was largely controlled by penecontemporaneous faults and/or fractures. This suggests that the micrographic intergrowths were formed in specific parts within a pluton where decompression as well as vapor exsolution was rapid enough to result in moderate degree of undercooling.

Key words

Masanite micrographic granite degree of undercooling decompression 


  1. Barker, D.S., 1970, Compositions of granophyre, myrmekite and graphic granite. Geological Society of America Bulletin, 81, 3339–3350.CrossRefGoogle Scholar
  2. Buddington, A.F., 1959, Granite emplacement with special reference to North America. Geological Society of America Bulletin, 70, 671–747.CrossRefGoogle Scholar
  3. Buddington, A.F. and Lindsley, D.H., 1964, Iron-titanium oxide minerals and synthetic equivalents. Journal of Petrology, 5, 310–357.Google Scholar
  4. Burnham, C.W., 1979, Magmas and hydrothermal fluids. In: Barnes, H.L. (ed.), Geochemistry of Hydrothermal Ore Deposits (2nd edn.). John Wiley, New York, p. 71–136.Google Scholar
  5. Candela, P.A., 1997, A review of shallow, ore-related granites: textures, volatiles, and ore metals. Journal of Petrology, 38, 1619–1633.CrossRefGoogle Scholar
  6. Chorlton, L.B. and Martin, R.F., 1978, The effect of boron on the granite solidus. Canadian Mineralogist, 16, 239–244.Google Scholar
  7. Coleman, R.G., DeBari, S. and Peterman, G., 1992, A-type granite and the Red Sea opening. Tectonophysics, 204, 27–40.CrossRefGoogle Scholar
  8. Dunham, A.C., 1965, The nature and origin of groundmass textures in felsites and granophyres from Rhum, Inverness-shire. Geological Magazine, 102, 8–23.Google Scholar
  9. Fenn, P.M., 1986, On the origin of graphic granite. American Mineralogist, 71, 325–330.Google Scholar
  10. Hammarstrom, J.M. and Zen, E., 1986, Aluminum in hornblende: an empirical igneous geobarometer. American Mineralogist, 71, 1297–1313.Google Scholar
  11. Hollister, L.S., Grissom, G.C., Peters, E.K., Stowell, H.H. and Sisson, V.B., 1987, Confirmation of the empirical correlation of Al in hornblende with pressure of solidification of calcalkaline plutons. American Mineralogist, 72, 231–239.Google Scholar
  12. Jahns, R.H., Martin, R.F. and Tuttle, O.F., 1969, Origin of granophyre in dikes and sills of tholeiitic diabase. 50th Annual Meeting of American Geophysical Union (Abstract), p. 337.Google Scholar
  13. James, R.S. and Hamilton, D.L., 1969, Phase relations in the system NaAlSi3O8−KAlSi3O8−CaAl2Si2O8−SiO2 at 1 kilobar water vapor pressure. Contributions to Mineralogy and Petrology, 21, 111–141.CrossRefGoogle Scholar
  14. Jin, M.S., 1985, Geochemistry of the Cretaceous to early Tertiary granitic rocks in southern Korea: Part I. Major elements geochemistry. Journal of the Geological Society of Korea, 21, 297–316.Google Scholar
  15. Jin, M.S., 1988, Geochemistry of the Cretaceous to early Tertiary granitic rocks in southern Korea: Part II. Trace elements geochemistry. Journal of the Geological Society of Korea, 24, 168–188.Google Scholar
  16. Johnson, M.C. and Rutherford, M.J., 1989, Experimental calibration of the aluminium-in-hornblende geobarometer with application to Long Valley caldera (California) volcanic rocks. Geology, 17, 837–841.CrossRefGoogle Scholar
  17. Kays, M.A., McBirney, A.R. and Goles, G.G., 1981, Xenoliths of gneisses and the conformable, clot-like granophyres in the Marginal Border Group, Skaergaard intrusion, East Greenland. Contributions to Mineralogy and Petrology, 76, 265–284.CrossRefGoogle Scholar
  18. Koto, B., 1909, Journeys through Korea (first contribution). Journal of College of Science (Imperial University of Tokyo), 26, 1–207.Google Scholar
  19. Lee, J.I., 1991, Petrology, Mineralogy and Isotopic Study of the Shallow-Depth Emplaced Granitic Rocks, Southern Part of the Kyeongsang Basin, Korea: Origin of Micrographic Granite. Ph.D. thesis, University of Tokyo, Tokyo, 197 p.Google Scholar
  20. Lee, J.I., 1992, Mineralogy and petrology of the shallow-depth emplaced granitic rocks distributed in the southern part of the Kyeongsang basin, Korea. Journal of the Korean Earth Science Society, 13, 176–199.Google Scholar
  21. Lee, J.I., 1994, Major element geochemistry of the shallow-depth emplaced granitic rocks, southern part of the Kyeongsang basin, Korea. Journal of the Geological Society of Korea, 30, 482–496.Google Scholar
  22. Lee, J.I., 1997, Trace and rare earth element geochemistry of the granitic rocks, southern part of the Kyongsang Basin, Korea. Geoscience Journal, 1, 167–178.CrossRefGoogle Scholar
  23. Lee, J.I., Kagami, H. and Nagao, K., 1995, Rb−Sr and K−Ar age determinations of the granitic rocks in the southern part of the Kyeongsang basin, Korea: implication for cooling history and evolution of granitic magmatism during late Cretaceous. Geochemical Journal, 29, 363–376.Google Scholar
  24. Lee, S.M., 1972, Granites and mineralization in Gyeongsang basin. Memories in Celebration of 60th Birthday of Professor Son, C.M. College Liberal Arts Science (Seoul National University), Seoul, p. 195–219. (in Korean with English abstract)Google Scholar
  25. Lentz, D.R. and Fowler, A.D., 1992, A dynamic model for graphic quartz-feldspar intergrowths in granitic pegmatites in the southwestern Grenville Province. Canadian Mineralogist, 30, 571–585.Google Scholar
  26. Lofgren, G., 1974, An experimental study of plagioclase crystal morphology: isothermal crystallization. American Journal of Science, 274, 243–273.Google Scholar
  27. Lowenstern, J.B., Clynne, M.A. and Bullen, T.D., 1997, Comagmatic A-type granophyre and rhyolite from the Alid volcanic center, Eritrea, Northeast Africa. Journal of Petrology, 38, 1707–1721.CrossRefGoogle Scholar
  28. Manning, D.A.C., 1981, The effect of fluorine on liquidus phase relationships in the system Qz-Ab-Or with excess water at 1 kb. Contributions to Mineralogy and Petrology, 76, 206–215.CrossRefGoogle Scholar
  29. Matsuhisa, Y., Goldsmith, J.R. and Clayton, R.N., 1979, Oxygen isotopic fractionation in the system quartz-albite-anorthite-water. Geochimica et Cosmochimica Acta, 43, 1131–1140.CrossRefGoogle Scholar
  30. McBirney, A.R., 1984, Igneous Petrology. Freeman, San Francisco, 509 p.Google Scholar
  31. McMillan, P.F. and Holloway, J.R., 1987, Water solubility in aluminosilicate melts. Contributions to Mineralogy and Petrology, 97, 320–332.CrossRefGoogle Scholar
  32. Naney, M.T., 1983, Phase equilibria of rock-forming ferromagnesian silicates in granitic systems. American Journal of Science, 282, 993–1033.Google Scholar
  33. Naney, M.T. and Swanson, S.E., 1980, The effect of Fe and Mg on crystallization in granitic systems. American Mineralogist, 65, 639–653.Google Scholar
  34. Pichavant, M., 1987, Effects of B and H2O on liquidus phase relations in the haplogranite system at 1 kbar. American Mineralogist, 72, 1056–1070.Google Scholar
  35. Schmidt, M.W., 1992, Amphibole composition in tonalite as a function of pressure: an experimental calibration of the Al-inhornblende barometer. Contributions to Mineralogy and Petrology, 110, 304–310.CrossRefGoogle Scholar
  36. Spencer, K.J. and Lindsley, D.H., 1981, A solution model for coexisting iron-titanium oxides. American Mineralogist, 66, 1189–1201.Google Scholar
  37. Swanson, S.E. and Fenn, P.M., 1986, Quartz crystallization in igneous rocks. American Mineralogist, 71, 331–342.Google Scholar
  38. Taylor, H.P., Jr., 1968, The oxygen isotope geochemistry of igneous rocks. Contributions to Mineralogy and Petrology, 19, 1–71.CrossRefGoogle Scholar
  39. Taylor, H.P., Jr., 1974, The application of oxygen and hydrogen isotope studies to problems of hydrothermal alteration and ore deposition. Economic Geology, 69, 843–883.Google Scholar
  40. Taylor, H.P., Jr., 1977, Water/rock interactions and the origin of H2O in granitic batholiths. Journal of the Geological Society (London), 133, 509–558.CrossRefGoogle Scholar
  41. Tuttle, O.F. and Bowen, N.L., 1958, Origin of Granite in the Light of Experimental Studies in the System NaAlSi3O8−KAlSi3O8−SiO2−H2O. Geological Society of America, Memoir, 74, 153 p.Google Scholar
  42. Westrich, H.R., Stockman, H.W. and Eichelberger, J.C. 1988, Degassing of rhyolitic magma during ascent and emplacement. Journal of Geophysical Research, 93, 6503–6511.CrossRefGoogle Scholar
  43. Whitney, J.A., 1975, The effects of pressure, temperature and\(X_{H_2 O} \) on phase assemblage in four synthetic rock compositions. Journal of Geology, 83, 1–31.Google Scholar
  44. Whitney, J.A., 1989, Origin and evolution of silicic magmas. In: Whitney, J.A. and Naldrett, A.J. (eds.), Ore Deposition Associated with magmas. Reviews in Economic Geology, 4, 183–201.Google Scholar

Copyright information

© Springer 1997

Authors and Affiliations

  1. 1.Polar Research CenterKorea Ocean Research and Development InstituteSeoulKorea

Personalised recommendations