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American Mineralogist

Journal of Earth and Planetary Materials

Ed. by Baker, Don / Xu, Hongwu / Swainson, Ian

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Volume 102, Issue 1


An integrated EPMA-EBSD study of metamorphic histories recorded in garnet

Masaki Enami
  • Corresponding author
  • Center for Chronological Research, Nagoya University, Nagoya 464-8602, Japan
  • Present address: Institute for Space-Earth Environmental Research, Nagoya University, Nagoya 464-8601, Japan
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/ Takayoshi Nagaya
  • Department of Earth and Planetary Sciences, Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601, Japan
  • Present address: Department of Environmental Studies for Advanced Society, Graduate School of Environmental Studies, Tohoku University, Sendai 980-8579, Japan
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/ Maw Maw Win
  • Department of Earth and Planetary Sciences, Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8601, Japan
  • Present address: Yadanabon University, Amarapura, Mandalay, Myanmar
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Published Online: 2017-01-03 | DOI: https://doi.org/10.2138/am-2017-5666


Growth histories recorded in garnet grains in metasedimentary rocks from the Sanbagawa belt in Japan and the Mogok belt in Myanmar were analyzed using an effective combination of electron backscatter diffraction (EBSD) and electron probe microanalysis (EPMA) data. Garnet in the Sanbagawa metapelite has inner and outer zones that formed in the eclogite and epidote-amphibolite facies stages, respectively. Based on EPMA element mapping, this garnet appears to have grown as a single crystal with a temporal break in growth between the inner and outer zones that occurred during exhumation. The EBSD data, however, document that the garnet grain is composed of four domains. The misorientation angles of crystallographic orientations between the domains are as large as 59°, and domain boundaries crosscut the growth zoning and the compositional boundary between the inner and outer zones. Sets of quartz grains included in the garnets on either side of the domain boundaries sometimes share the same crystallographic orientation with misorientation angles less than 4°. The garnet grains formed via a three-step process of prograde crystallization of polycrystalline garnet during the eclogite facies stage (inner zone) → resorption around garnet rims and along domain boundaries during exhumation → crystallization of the outer zone and in the domain boundaries during the prograde epidote-amphibolite facies stage.

The garnet porphyroblasts in the Mogok pelitic gneisses, which formed during prograde metamorphism to the upper amphibolite-granulite facies (0.6–1.0 GPa/780–850 °C), are now separated into segments of various sizes by mosaic or symplectite aggregates of biotite, plagioclase, and quartz or monomineralic biotite veins. The segment texture formed at about 0.3–0.4 GPa/610–650 °C or lowergrade conditions. The EBSD analysis shows that most of the segments share the same crystallographic orientation with misorientation angles less than 4° and show no evidence of deformation and/or rotation processes after segmentation. These data suggest that the Mogok sample did not experience dynamic deformation of the garnet grains after the resorption and segmentation stage and may have been exhumed under static conditions from depths of 9–12 km.

Keywords: EBSD; EPMA; garnet; polycrystals; growth process; metamorphism

References cited

  • Aoki, K., Kitajima, K., Masago, H., Nishizawa, M., Terabayashi, M., Omori, S., Yokoyama, T., Takahata, N., Sano, Y., and Maruyama, S. (2009) Metamorphic P-T-time history of the Sanbagawa Belt in central Shikoku, Japan and implications for retrograde metamorphism during exhumation. Lithos, 113, 393–407.Google Scholar

  • Aoya, M. (2001) P-T-D path of eclogite from the Sambagawa belt deduced from combination of petrological and microstructural analyses. Journal of Petrology, 42, 1225–1248.Google Scholar

  • Banno, S. (1965) Notes on rock-forming minerals (34) zonal structure of pyralspite garnet in Sanbagawa schists in the Bessi area, Sikoku. Journal of Geological Society of Japan, 71, 185–188.Google Scholar

  • Banno, S., and Sakai, C. (1989) Geology and metamorphic evolution of the Sanbagawa metamorphic belt, Japan. In J.S. Daly, R.A. Cliff, and B.W.D. Yardley, Eds., The Evolution of Metamorphic Belts, 43, p. 519–532. Blackwell Scientific Publications, Oxford.Google Scholar

  • Barley, M.E., Pickard, A.L., Khin Zaw, Rak, P., and Doyle, M.G. (2003) Jurassic to Miocene magmatism and metamorphism in the Mogok metamorphic belt and the India-Eurasia collision in Myanmar. Tectonics, 22.Google Scholar

  • Bhattacharya, A., Mohanty, L., Maji, A., Sen, S.K., and Raith, M. (1992) Non-ideal mixing in the phlogopite-annite binary: constraints from experimental data on Mg-Fe partitioning and a reformulation of the biotite-garnet geothermometer. Contributions to Mineralogy and Petrology, 111, 87–93.Google Scholar

  • Cheng, H., Nakamura, E., Kobayashi, K., and Zhou, Z. (2007) Origin of atoll garnets in eclogites and implications for the redistribution of trace elements during slab exhumation in a continental subduction zone. American Mineralogist, 92, 1119–1129.Google Scholar

  • Enami, M. (1983) Petrology of pelitic schists in the oligoclase-biotite zone of the Sanbagawa metamorphic terrain, Japan: phase equilibria in the highest grade zone of a high-pressure intermediate type of metamorphic belt. Journal of Metamorphic Geology, 1, 141–161.Google Scholar

  • Enami, M., Wallis, S.R., and Banno, Y. (1994) Paragenesis of sodic pyroxene-bearing quartz schists: implications for the P-T history of the Sanbagawa belt. Contributions to Mineralogy and Petrology, 116, 182–198.Google Scholar

  • Enami, M., Nishiyama, T., and Mouri, T. (2007) Laser Raman microspectrometry of metamorphic quartz: A simple method for comparison of metamorphic pressures. American Mineralogist, 92, 1303–1315.Google Scholar

  • Endo, S. (2010) Pressure-temperature history of titanite-bearing eclogite from the Western Iratsu body, Sanbagawa metamorphic belt, Japan. Island Arc, 19, 313–335.Google Scholar

  • Endo, S., and Tsuboi, M. (2013) Petrogenesis and implications of jadeite-bearing kyanite eclogite from the Sanbagawa belt (SW Japan). Journal of Metamorphic Geology, 31, 647–661.Google Scholar

  • Fliervoet, T.F., White, S.H., and Drury, M.R. (1997) Evidence for dominant grain-boundary sliding deformation in greenschist- and amphibolite-grade polymineralic ultramylonites from the Redbank Deformed Zone, Central Australia. Journal of Structural Geology, 19, 1495–1520.Google Scholar

  • Griffiths, T.A., Habler, G., Rhede, D., Wirth, R., Ram, F., and Abart, R. (2014) Localization of submicron inclusion re-equilibration at healed fractures in host garnet. Contributions to Mineralogy and Petrology, 168, 1077.Google Scholar

  • Higashino, T. (1990) The higher-grade metamorphic zonation of the Sambagawa metamorphic belt in central Shikoku, Japan. Journal of Metamorphic Geology, 8, 413–423.Google Scholar

  • Hirsch, D.M., Prior, D.J., and Carlson, W.D. (2003) An overgrowth model to explain multiple, dispersed high-Mn regions in the cores of garnet porphyroblasts. American Mineralogist, 88, 131–141.Google Scholar

  • Holdaway, M.J. (2000) Application of new experimental and garnet Margules data to the garnet-biotite geothermometer. American Mineralogist, 85, 881–892.Google Scholar

  • Kabir, M.F., and Takasu, A. (2010) Evidence for multiple burial–partial exhumation cycles from the Onodani eclogites in the Sambagawa metamorphic belt, central Shikoku, Japan. Journal of Metamorphic Geology, 28, 873–893.Google Scholar

  • Kaneko, Y. (1997) Two-step exhumation model of the Himalayan metamorphic belt, central Nepal. Journal of Geological Sociery of Japan, 103, 203–226.Google Scholar

  • Kato, T. (2005) New accurate Bence-Albee α-factors for oxides and silicates calculated from the PAP correction procedure. Geostandrds and Geoanalytical Research, 29, 83–94.Google Scholar

  • Kleinschrodt, R., and Duyster, J.P. (2002) HT-deformation of garnet: an EBSD study on granulites from Sri Lanka, India and the Ivrea Zone. Journal of Structural Geology, 24, 1829–1844.Google Scholar

  • Kouketsu, Y., and Enami, M. (2010) Aragonite and omphacite-bearing metapelite from Besshi region, Sambagawa belt in central Shikoku, Japan and its implication. Island Arc, 19, 165–176.Google Scholar

  • (2011) Calculated stabilities of sodic phases in the Sambagawa metapelites and their implications. Journal of Metamorphic Geology, 29, 301–316.Google Scholar

  • Kouketsu, Y., Enami, M., and Mizukami, T. (2010) Omphacite-bearing metapelite from the Besshi region, Sambagawa metamorphic belt, Japan: Prograde eclogite facies metamorphism recorded in metasediment. Journal of Mineralogical and Petrological Sciences, 105, 9–19.Google Scholar

  • Kouketsu, Y., Enami, M., Mouri, T., Okamura, M., and Sakurai, T. (2014a) Composite metamorphic history recorded in garnet porphyroblasts of Sambagawa metasediments in the Besshi region, central Shikoku, Southwest Japan. Island Arc, 23, 263–280.Google Scholar

  • Kouketsu, Y., Nishiyama, T., Ikeda, T., and Enami, M. (2014b) Evaluation of residual pressure in host-inclusion system using the negative frequency shift of quartz Raman spectrum. American Mineralogist, 99, 433–442.Google Scholar

  • Kugimiya, Y., and Takasu, A. (2002) Geology of the Western Iratsu mass within the tectonic melange zone in the Sambagawa metamorphic belt, Besshi district, central Shikoku, Japan. Journal of Geological Society of Japan, 108, 644–662 (in Japanese with English abstract).Google Scholar

  • Levien, L., Prewitt, C.T., and Weidner, D.J. (1980) Structure and elasticproperties of quartz at pressure. American Midland Naturalist, 65, 920–930.Google Scholar

  • Licht, A., France-Lanord, C., Reisberg, L., Fontaine, C., Soe, A.N., and Jaeger, J.J. (2013) A palaeo Tibet-Myanmar connection? Reconstructing the Late Eocene drainage system of central Myanmar using a multi-proxy approach. Journal of Geological Society, London, 170, 929–939.Google Scholar

  • Mainprice, D.A. (1990) Fortran program to calculate seismic anisotropy from the lattice preferred orientation of minerals. Computers & Geosciences, 16, 385–393.Google Scholar

  • Maw Maw Win, Enami, M., and Kato, T. (2016) Metamorphic conditions and CHIME monazite ages of Late Eocene to Late Oligocene high-temperature Mogok metamorphic rocks in central Myanmar. Journal of Asian Earth Sciences, 117, 304–316.Google Scholar

  • Mitchell, A.H.G., Myint Thein Htay, Kyaw Min Htun, Myint Naing Win, Thura Oo, and Tin Hlaing (2007) Rock relationships in the Mogok metamorphic belt, Tatkon to Mandalay, central Myanmar. Journal of Asian Earth Sciences, 29, 891–910.Google Scholar

  • Miyagi, Y., and Takasu, A. (2005) Prograde eclogites from the Tonaru epidote amphibolite mass in the Sambagawa Metamorphic Belt, central Shikoku, southwest Japan. Island Arc, 14, 215–235.Google Scholar

  • Miyamoto, A., Enami, M., Tsuboi, M., and Yokoyama, K. (2007) Peak conditions of kyanite-bearing quartz eclogites in the Sanbagawa metamorphic belt, central Shikoku, Japan. Journal of Mineralogical and Petrological Sciences, 102, 352–367.Google Scholar

  • Mouri, T., and Enami, M. (2008) Areal extent of eclogite facies metamorphism in the Sanbagawa belt, Japan: New evidence from a Raman microprobe study of quartz residual pressure. Geology, 36, 503–506.Google Scholar

  • Nagaya, T., Wallis, S.R., Kobayashi, H., Michibayashi, K., Mizukami, T., Seto, Y., Miyake, A., and Matsumoto, M. (2014) Dehydration breakdown of antigorite and the formation of B-type olivine CPO. Earth and Planetary Science Letters, 387, 67–76.Google Scholar

  • Novak, G.A., and Gibbs, G.V. (1971) The crystal chemistry of the silicate garnets. American Mineralogist, 56, 791–825.Google Scholar

  • Okamoto, A., and Michibayashi, K. (2006) Misorientations of garnet aggregate within a vein; an example from the Sanbagawa metamorphic belt, Japan. Journal of Metamorphic Geology, 24, 353–366.Google Scholar

  • Ota, T., Terabayashi, M., and Katayama, I. (2004) Thermobaric structure and metamorphic evolution of the Iratsu eclogite body in the Sanbagawa belt, central Shikoku, Japan. Lithos, 73, 95–126.Google Scholar

  • Padrón-Navarta, J.A., Tommasi, A., Garrido, C.J., and Sánchez-Vizcaíno, V.L. (2012) Plastic deformation and development of antigorite crystal preferred orientation in high-pressure serpentinites. Earth and Planetary Science Letters, 349-350, 75–86.Google Scholar

  • Pattison, D.R.M. (2001) Instability of Al2SiO5 “triple-point” assemblages in muscovite+biotite+quartz-bearing metapelites, with implications. American Mineralogist, 86, 1414–1422.Google Scholar

  • Prior, D.J., Wheeler, J., Brenker, F.E., Harte, B., and Matthews, M. (2000) Crystal plasticity of natural garnets: new microstructural evidence. Geology, 28, 1003–1006.Google Scholar

  • Robyr, M., Vonlanthen, P., Baumgartner, L.P., and Grobety, B. (2007) Growth mechanism of snowball garnets from the Lukmanier Pass area (Central Alps, Switzerland): a combined µCT/EPMA/EBSD study. Terra Nova, 19, 240–244.Google Scholar

  • Ruiz Cruz, M.D. (2011) Origin of atoll garnet in schists from the Alpujarride Complex (Central zone of the Betic Cordillera, Spain): Implications on the P-T evolution. Mineralogy and Petrology, 101, 245–261.Google Scholar

  • Sakurai, T., and Takasu, A. (2009) Geology and metamorphism of the Gazo mass (eclogite-bearing tectonic block) in the Sambagawa metamorphic belt, Besshi district, central Shikoku, Japan. Journal of Geological Society of Japan, 115, 101–121 (in Japanese with English abtract).Google Scholar

  • Schertl, H.P., and Neuser, R.D. (2007) Unusual lath-shaped garnet-zoisite inter-growth textures from a UHP zoisite-quartz fels, Dora Maira, northwest Italy: An EBSD case study. International Geology Review, 49, 626–635.Google Scholar

  • Searle, M.P., Noble, S.R., Cottle, J.M., Waters, D.J., Mitchell, A.H.G., Tin Hlaing, and Horstwood, M.S.A. (2007) Tectonic evolution of the Mogok metamorphic belt, Burma (Myanmar) constrained by U-Th-Pb dating of metamorphic and magmatic rocks. Tectonics, 26, TC3014.Google Scholar

  • Spear, F.S., and Cheney, J.T. (1989) A petrogenetic grid for pelitic schists in the system SiO2-Al2O3-FeO-MgO-K2O-Na2O-H2O. Contributions to Mineralogy and Petrology, 101, 149–164.Google Scholar

  • Spear, F.S., Kohn, M.J., Florence, F.P., and Menard, T. (1990) A model for garnet and plagioclase growth in pelitic schists; implications for thermobarometry P-T path determinations. Journal of Metamorphic Geology, 8, 683–696.Google Scholar

  • Spiess, R., Peruzzo, L., Prior, D.J., and Wheeler, J. (2001) Development of garnet porphyroblasts by multiple nucleation, coalescence and boundary misorientation-driven rotations. Journal of Metamorphic Geology, 19, 269–290.Google Scholar

  • Storey, C.D., and Prior, D.J. (2005) Plastic deformation and recrystallization of garnet: A mechanism to facilitate diffusion creep. Journal of Petrology, 46, 2593–2613.Google Scholar

  • Taguchi, T., and Enami, M. (2014) Compositional zoning and inclusions of garnet in Sanbagawa metapelites from the Asemi-gawa route, central Shikoku, Japan. Journal of Mineralogical and Petrological Sciences, 109, 1–12.Google Scholar

  • Takasu, A. (1984) Prograde and retrograde eclogites in the Sambagawa metamorphic belt, Besshi district, Japan. Journal of Petrology, 25, 619–643.Google Scholar

  • Thompson, A.B., Tracy, R.J., Lyttle, P., and Thompson, J.B.J. (1977) Prograde reaction histories deduced from compositional zonation and mineral inclusions in garnet from the Gassetts schist, Vermont. American Journal of Science, 277, 1152–1167.Google Scholar

  • Vollbrecht, A., Pawlowski, J., Leiss, B., Heinrichs, T., Seidel, M., and Kronz, A. (2006) Ductile deformation of garnet in mylonitic gneisses from the Munchberg Massif (Germany). Tectonophysics, 427, 153–170.Google Scholar

  • Wallis, S., Takasu, A., Enami, M., and Tsujimori, T. (2000) Eclogite and related metamorphism in the Sanbagawa belt, Southwest Japan. Bulletin of Research Institute of Natural Sciences, Okayama University of Science, 26, 3–17.Google Scholar

  • Whitney, D.L., and Evans, B.W. (2010) Abbreviations for names of rock-forming minerals. American Mineralogist, 95, 185–187.Google Scholar

  • Whitney, D.L., and Seaton, N.C.A. (2010) Garnet polycrystals and the significance of clustered crystallization. Contributions to Mineralogy and Petrology, 160, 591–607.Google Scholar

  • Whitney, D.L., Goergen, E.T., Ketcham, R.A., and Kunze, K. (2008) Formation of garnet polycrystals during metamorphic crystallization. Journal of Metamorphic Geology, 26, 365–383.Google Scholar

  • Wu, C.-M., Zhang, J., and Ren, L.-D. (2004) Empirical garnet-biotite-plagioclase-quartz (GBPQ) geobarometry in medium- to high-grade metapelites. Journal of Petrology, 45, 1907–1921.Google Scholar

  • Ye Kyaw Thu, Maw Maw Win, Enami, M., and Tsuboi, M. (2016) Ti-rich biotite in spinel and quartz-bearing paragneiss and related rocks from the Mogok metamorphic belt, central Myanmar. Journal of Mineralogical and Petrological Sciences, 111, 270–282, .CrossrefGoogle Scholar

  • Zaw Win Ko, Enami, M., and Aoya, M. (2005) Chloritoid and barroisite-bearing pelitic schists from the eclogite unit in the Besshi district, Sanbagawa meta-morphic belt. Lithos, 81, 79–100.Google Scholar

About the article

Received: 2015-12-28

Accepted: 2016-08-29

Published Online: 2017-01-03

Published in Print: 2017-01-01

Citation Information: American Mineralogist, Volume 102, Issue 1, Pages 192–204, ISSN (Online) 1945-3027, ISSN (Print) 0003-004X, DOI: https://doi.org/10.2138/am-2017-5666.

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