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MnNCKFMASH phase relations in cordierite-orthopyroxene migmatitic gneisses, southern india: implications for low-pressure crustal melting under granulite-facies

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Journal of the Geological Society of India

Abstract

Cordierite-orthopyroxene migmatitic gneisses exposed in Achankovil unit of the Kerala Khondalite Belt, southern India show evidences of melting, melt extraction and in-situ crystallization of melt under granulite-facies conditions. The sequential mineral assemblages garnet + biotite + orthopyroxene + plagioclase + quartz (± melt) in the mesosomes and garnet + biotite + orthopyroxene + cordierite + plagioclase + K-feldspar + quartz + melt in the melanosomes makes the Achankovil cordierite-orthopyroxene migmatitic gneisses a good example of anatectic rocks, where substantial melt fractions remained in-situ during decompression and cooling. Therefore, the rocks provide an opportunity to investigate deep crustal processes and record of rheological (thermal and mechanical) reequilibration prevailed during the final stages of orogeny.

The significance of cordierite formation and its possible relationship with melt formation are investigated applying theoretical calculations in the MnO-Na2O-CaO-K2O-FeO-MgO-Al2O3-SiO2-H2O (MnNCKFMASH) system. Results of numerical modelling of the mineral assemblages in pressure-temperature-composition (P-T-X) pseudosections using Perple_X infer that the sequence of reactions involving formation of cordierite-orthopyroxene-melt assemblage is consistent with an isothermal decompression (with a pressure drop of >1.5 kbars) at high temperatures (>800 °C), forming leucosomes. Biotite dehydration melting reactions, occurring above 4.5 kbars constrain prograde arm of the P-T trajectory and is interpreted as a product of crustal thickening, which was followed by rapid decompression. The final stage of exhumation is characterized by rehydration of cordierites in the melanosome by melt-solid interactions at exceptionally low-pressure (∼3.2 kbars) conditions. The high-temperature isothermal decompression inferred from the mineral reactions and P-T-X pseudosections constitute a clockwise P-T path for the exhumation of the lower crust. This clockwise P-T path is consistent with the common tectonic model accepted for the genesis of granulite-facies migmatites during crustal thickening and later unroofing, accompanied with arc-continent collision. Our conclusions indicate low-P metamorphism and anatexis can be traced to convergent setting, where melt buoyancy considerably decreases density of the lithosphere and modifies rheology leading to rapid exhumation of the lower crust. Therefore, the crustal evolution in the Kerala Khondalite Belt is correlated with two stage processes: (i) thickening of the crust in relation to a continental-arc setting, followed by (ii) exhumation along a high-temperature stable geotherm with sufficient pressure release associated with syn- to post-convergence transpression and transtension.

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References

  • Ashworth, J.R. and Mclellan, E.L. (1985) Textures. In: J.R. Ashworth (Ed.), Migmatites. Chapman and Hall, New York, pp.180–203.

    Chapter  Google Scholar 

  • Black, R. and Liégeois, J.-P. (1993) Cratons, mobile belts, alkaline rocks and continental lithospheric mantle: the Pan-African testimony. Jour. Geol. Soc., London, v.150, pp.89–98.

    Article  Google Scholar 

  • Bodorkos, S., Sandiford, M., Oliver, N.H.S. and Cawood, P.A. (2002) High-T, low-P metamorphism in the Palaeoproterozoic Hall’s Creek Orogen, northern Australia: the middle crustal response to a mantle-related thermal pulse. Jour. Metamorph. Geol., v.20, pp.217–237.

    Article  Google Scholar 

  • Bonin, B., Azzuni-sekkal, A., Bussy, F. and Ferrag, S. (1998) Alkali-calcic and alkaline post-orogenic (PO) granite magmatism: petrologic constraints and geodynamic settings. Lithos, v.45, pp.45–70.

    Article  Google Scholar 

  • Braun, I. (1996) Pan-African granitic magmatism in the Kerala Khondalite Belt, southern India. Jour. Asian Earth Sci., v.28, pp.38–45.

    Article  Google Scholar 

  • Braun, I., Ravindra Kumar, G.R. and Raith, M. (1996) Dehydration-melting phenomena in leptynitic gneisses and the generation of leucogranites: a case study from the Kerala Khondalite Belt, southern India. Jour. Petrol., v.37, pp.1285–1305.

    Article  Google Scholar 

  • Braun, I., Montel, J.-M. and Nicollet, C. (1998) Electron microprobe dating of monazites from high-grade gneisses and pegmatites of the Kerala Khondalite Belt, southern India. Chem. Geol., v.146, pp.65–85.

    Article  Google Scholar 

  • Braun, I. and Kriegsman, L.M. (2003) Proterozoic crustal evolution in southernmost India and Sri Lanka. In: M. Yoshida, B.F. Windley and S. Dasgupta (Eds.), Proterozoic East Gondwana: Supercontinent Assembly and Breakup. Spec. Publ., Geol. Soc., London, v. 206, pp.169–202.

    Google Scholar 

  • Brown, M. (1983) The petrogenesis of some migmatites from the Presqu’ile de Rhuys, southern Brittany, France. In: M.P. Atherton and C.D. Gribble (Eds), Migmatites, Melting and Metamorphism. Shiva, Nantwich, pp.174–200.

    Google Scholar 

  • Brown, M. (1994) The generation, segregation, ascent and emplacement of granite magma: the migmatite-to-crustallyderived granite connection in thickened orogens. Earth-Sci. Rev., v.36, pp.83–130.

    Article  Google Scholar 

  • Brown, M. (2001) From microscope to mountain belt. 150 years of petrology and its contribution to understanding the tectonics of orogens. Jour. Geodyn., v.32, pp.115–164.

    Article  Google Scholar 

  • Brown, M. and Raith, M. (1996) First evidence of ultrahightemperature decompression from the granulite province of southern India Jour. Geol. Soc., London, v.153, pp.819–822.

    Article  Google Scholar 

  • Cenki, B., Kriegsman, L.M. and Braun, I. (2002) Melt-producing and melt-consuming reactions in the Achankovil cordierite gneisses, South India. Jour. Metamorph. Geol., v.20, pp.543–561.

    Article  Google Scholar 

  • Chacko, T., Ravindra Kumar, G.R. and Newton, R.C. (1987) Metamorphic P-T conditions of Kerala (s. India) khondalite belt: a granulite-facies supracrustal terrain. Jour. Geol., v.95, pp.343–358.

    Article  Google Scholar 

  • Chacko, T., Ravindra Kumar, G.R., Meen, J.K. and Rogers, J.J.W. (1992) Geochemistry of the high-grade supracrustal rocks from the Kerala khondalite belt, South India. Precam. Res., v.55, pp.469–489.

    Article  Google Scholar 

  • Clarke, D.B. (1995) Cordierite in felsic igneous rocks- a Synthesis. Mineral. Mag., v.59, pp.311–325.

    Article  Google Scholar 

  • Connolly, J.A.D. (1990) Multivariable phase diagrams: an algorithm based on generalized thermodynamics. Am. Jour. Sci., v.290, pp.666–718.

    Article  Google Scholar 

  • Connolly, J.A.D. (2009) The geodynamic equation of state: what and how? Geochem. Geophy. Geosys., v.10, Q10014, 19p.

    Article  Google Scholar 

  • Connolly, J.A.D. and Petrini, K. (2002) An automated strategy for calculation of phase diagram sections and retrieval of rock properties as a function of physical conditions. Jour. Metamorph. Geol., v.20, pp.697–708.

    Article  Google Scholar 

  • De Capitani, C. and Petrakakis, K. (2010) The computation of equilibrium assemblage diagrams with Theriak/Domino software, Am. Mineral., v.95, pp.1006–1016.

    Article  Google Scholar 

  • England, P.C. and Richardson, S.W. (1977) The influence of erosion upon the mineral facies of rocks from different metamorphic environments. Jour. Geol. Soc., London, v.134, pp.201–213.

    Article  Google Scholar 

  • England, P.C. and Thompson, A.B. (1984) Pressure-temperaturetime paths of regional metamorphism. Part I: Heat-transfer during the evolution of regions of thickened continental crust. Jour. Petrol., v.25, pp.894–928.

    Article  Google Scholar 

  • Faccenda, M., Gerya, T.V. and Chakraborty, S. (2008) Styles of post-subduction collisional orogeny: influence of convergence velocity, crustal rheology and radiogenic heat production. Lithos, v.103, pp.257–287.

    Article  Google Scholar 

  • Faccenda, M., Minelli, G. and Gerya, T.V. (2009). Coupled and decoupled regimes of continental collision: numerical modeling. Earth Planet. Sci. Lett., v.278, pp.337–349.

    Article  Google Scholar 

  • Gerbi, C.C., Johnson, S.E. and Koons, P.O. (2006) Controls on low-pressure anatexis. Jour. Metamorph. Geol., v.24, pp.107–118.

    Article  Google Scholar 

  • Gerya, T.V. and Stöckhert, B. (2006) Two-dimensional numerical modeling of tectonic and metamorphic histories at active plate margins. Int. Jour. Earth Sci., v.95, pp.250–274.

    Article  Google Scholar 

  • Grant, J.A. (1985) Phase equilibria in partial melting of pelitic rocks. In: J.R. Ashworth (Ed.), Migmatites. Chapman and Hall, New York, pp.86–144.

    Chapter  Google Scholar 

  • GSI (1995) Geological maps of Andhra Pradesh, Karnataka, Kerala, Tamil Nadu, and Pondicherry on 1:500,000 scale. Geol. Surv. India, Calcutta.

    Google Scholar 

  • Harley, S.L. (1989) The origins of granulites: a metamorphic perspective. Geol. Mag., v.126, pp.215–247.

    Article  Google Scholar 

  • Hensen, B. J. (1971) Theoretical phase relations involving cordierite and garnet in the system MgO-FeO-Al2O3-SiO2. Contrib. Mineral. Petrol., v.33, pp.191–214.

    Article  Google Scholar 

  • Hensen, B.J. and Green, D.H. (1972) Experimental study of the stability of cordierite and garnet in pelitic compositions at high pressures and temperatures. II: Compositions without excess aluminosilicate. Contrib. Mineral. Petrol., v.35, pp.331–354.

    Article  Google Scholar 

  • Holland, T.J.B., Babu, E.V.S.S.K. and Waters, D.J. (1996) Phase relations of osumilite and dehydration melting in pelitic rocks: a simple thermodynamic model for the KFMASH system. Contrib. Mineral. Petrol., v.124, pp.383–394.

    Article  Google Scholar 

  • Holland, T.J.B. and Powell, R. (2011) An improved and extended internally consistent thermodynamic dataset for phases of petrological interest, involving a new equation of state for solids. Jour. Metamorph. Geol., v.29, pp.333–383.

    Article  Google Scholar 

  • Hollister, L.S. (1993) The role of melt in the uplift and exhumation of orogenic belts. Chem. Geol., v.108, pp.31–48.

    Article  Google Scholar 

  • Huerta, A.D., Royden, L.H. and Hodges, K.V. (1998) The thermal structure of collisional orogens as a response to accretion, erosion, and radiogenic heating. Jour. Geophys. Res., v.103, pp.15287–15302.

    Article  Google Scholar 

  • Huerta, A. D., Royden, L.H. and Hodges, K.V. (1999) The effects of accretion, erosion and radiogenic heat on the metamorphic evolution of collisional orogens. Jour. Metamorph. Geol., v.17, pp.349–366.

    Article  Google Scholar 

  • Johnson, T.E., Brown, M. and Solar, G.S. (2003) Low-pressure subsolidus and suprasolidus phase equilibria in the MnNCKFMASH system: constraints on conditions of regional metamorphism in western Maine, northern Appalachians. Am. Mineral., v.88, pp.624–638.

    Google Scholar 

  • Jones, K.A. and Brown, M. (1990) High-temperature ‘clockwise’ P-T paths and melting in the development regional of migmatites: an example from southern Brittany, France. Jour. Metamorph. Geol., v.8, pp.551–578.

    Article  Google Scholar 

  • Kelsey, D.E., White, R.W. and Powell, R. (2003) Orthopyroxenesillimanite-quartz assemblages: distribution, petrology, quantitative P-T-X constraints and P-T paths. Jour. Metamorph. Geol., v.21, pp.439–453.

    Article  Google Scholar 

  • Kriegsman, L.M. and Hensen, B.J. (1998) Back reaction between restite and melt: implications for geothermobarometry and pressure-temperature paths. Geology, v.26, pp.1111–1114.

    Article  Google Scholar 

  • Le Bayon, B., Pitra, P., Ballevre, M. and Bohn, M. (2006) Reconstructing P-T paths during continental collision using multi-stage garnet (Gran Paradiso nappe, Western Alps). Jour. Metamorph. Geol., v.24, pp.477–496.

    Article  Google Scholar 

  • Lux, D.R., Deyoreo, J.J., Guldotti, C.V. and Decker, E.R. (1986) Role of plutonism in low-pressure metamorphic belt formation. Nature, v.323, pp.794–797.

    Article  Google Scholar 

  • Mahar, E.M., Baker, J.M., Powell, R., Holland, T.J.B. and Howell, N. (1997) The effect of Mn on mineral stability in metapelites. Jour. Metamorph. Geol., v.15, pp.223–238.

    Article  Google Scholar 

  • Mckenzie, D. and Bickle, M.J. (1988) The volume and composition of melt generated by extension of lithosphere. Jour. Petrol., v.29, pp.625–679.

    Article  Google Scholar 

  • Mohan, A. and Jayananda, M. (1999) Metamorphism and isotopic evolution of granulites of Southern India: reference to Neoproterozoic crustal evolution. Gond. Res., v.2, pp.251–262.

    Article  Google Scholar 

  • Nandakumar, V. and Harley, S.L. (2000) A reappraisal of pressure-temperature conditions and P-T path of the Kerala Khondalite Belt. Jour. Geol., v.108, pp.687–703.

    Article  Google Scholar 

  • Pattison, D.R.M. and Tracy, R.J. (1991) Phase equilibria and thermobarometry of metapelites. In: D.M. Kerrick (Ed.), Contact Metamorphism. Rev. Mineral., Mineral. Soc. America, v.26, pp.105–206.

  • Platt, J.P. and England, P. (1994) Convective removal of lithosphere beneath mountain belts: thermal and mechanical consequences. Am. Jour. Sci., v.293, pp.307–336.

    Article  Google Scholar 

  • Powell, R. and Holland, T.J.B. (1988) An internally consistent dataset with uncertainties and correlations: 3. Applications to geobarometry, worked examples and a computer program. Jour. Metamorph. Geol., v.6, pp.173–204.

    Article  Google Scholar 

  • Rajesh, H.M. and Santosh, M. (1996) Alkaline magmatism in Peninsular India. In: M. Santosh and M. Yoshida, (Eds.), The Archaean and Proterozoic Terrains in Southern India within East Gondwana. Mem., Gondwana Res. Group, v.3, pp.91–116.

  • Ravindra Kumar, G.R. and Sreejith, C. (2010) Geochemistry of granitoids of the Kerala Khondalite Belt, Southern India-Magmatic petrogenesis in an arc-accretion setting. Goldschmidt Conf. Abst., Geochim. Cosmochim. Acta, v.74(12/1), pp.A851.

    Google Scholar 

  • Richet, P. and Bottinga, Y. (1995) Rheology and configurational entropy of silicate melts. In: J. Stebbins, P.F. McMillan and D.B. Dingwell (Eds.), Structure, Dynamics and Properties of Silicate Melts. Rev. Mineral., Min. Soc. Am., v.32, pp.67–93.

  • Rollinson, H.R. (1993) Using Geochemical Data: Evaluation, Presentation, Interpretation. Longman, UK. 352 p.

    Google Scholar 

  • Rubatto, D. and Hermann, J. (2001) Exhumation as fast as subduction? Geology, v.29, pp.3–6.

    Article  Google Scholar 

  • Sajeev, K., Osanai, Y. and Santosh, M. (2004) Ultrahightemperature metamorphism followed by two-stage decompression of garnet-orthopyroxene-sillimanite granulites from Ganguvarpatti, Madurai block, southern India. Contrib. Mineral. Petrol., v.148, pp.29–46.

    Article  Google Scholar 

  • Santosh, M. (1987) Cordierite gneisses of southern Kerala, India: petrology, fluid inclusions and implications for crustal uplift history. Contrib. Mineral. Petrol., v.96, pp.343–356.

    Article  Google Scholar 

  • Sawyer, E.W. (1999) Criteria for the recognition of partial melting. Phy. Chem. Earth (A): Solid Earth Geodesy, v.24, pp.269–279.

    Article  Google Scholar 

  • Shau, Y., Yang, H. and Peacor, D.R. (1991) On oriented titanite and rutile inclusions in sagenitic biotite. Am. Mineral., v.76, pp.1205–1217.

    Google Scholar 

  • Sinha-roy, S., Mathai, J. and Narayanaswami (1984) Structure and metamorphic characters of cordierite-bearing gneisses, south Kerala. Jour. Geol. Soc. India, v.25, pp.231–244.

    Google Scholar 

  • Spear, F.S., 1993. Metamorphic Phase Equilibria and Pressure-Temperature-Time Paths. Monogr., Min. Soc. Am., No.1, 799p.

  • Sreejith, C. and Ravindra Kumar, G.R. (2009) Petrological and geochemical characteristics of Marunthurkota syenites from the Kerala Khondalite Belt, southern India. Jour. Geol. Soc. India, v.73, pp.386–392.

    Article  Google Scholar 

  • Sreejith, C. and Ravindra Kumar, G.R. (2011) Geochemistry of K-feldspar megacryst granitoids of the Kerala Khondalite Belt: evidence for exposed roots of an accreted continental-arc system, Int. Symp., ‘Precambrian Accretionary Orogens’, Abst. Vol., Geol. Soc. India, pp.127–128.

  • Sreejith, C. and Ravindra Kumar, G.R. (2012) Petrogenesis of high-K metagranitoids in the Kerala Khondalite Belt, southern India: a possible magmatic-arc link between India, Sri Lanka, and Madagascar. Submitted to the Jour. Geodyn.

  • Srikantappa, C., Raith, M. and Spiering, B. (1985) Progressive charnockitisation of a leptynite-khondalite Suit in southern India, evidence for formation of charnockites through decrease in fluid pressure. Jour. Geol. Soc. India, v.26, pp.849–872.

    Google Scholar 

  • Stevens, G. and Clemens, J.D. (1993) Fluid-absent melting and the roles of fluids in the lithosphere: a slanted summary? Chem. Geol., v.108, pp.1–17.

    Article  Google Scholar 

  • Symmes, G.H. and Ferry, J.M. (1992) The effect of whole-rock MnO content on the stability of garnet in pelitic schists during metamorphism. Jour. Metamorph. Geol., v.10, pp.221–237.

    Article  Google Scholar 

  • Thompson, A.B. (1982) Dehydration melting of pelitic rocks and the generation of H2O-undersaturated granitic liquids: Am. Jour. Sci., v.282, pp.1567–1595.

    Article  Google Scholar 

  • Thompson, A.B. and England, P.C. (1984) Pressure-temperaturetime paths of regional metamorphism II. Their inference and interpretation using mineral assemblages in metamorphic rocks. Jour. Petrol., v.25, pp.929–955.

    Article  Google Scholar 

  • Thompson, J.B., Jr. (1957) The graphical analysis of mineral assemblages in pelitic schists. Am. Mineral., v.42, pp.842–858.

    Google Scholar 

  • Tinkham, D.K., Zuluaga, C.A. and Stowell, H.H. (2001) Metapelite phase equilibria modeling in MnNCKFMASH: the effect of variable Al2O3 and MgO/(MgO + FeO) on mineral stability. Geol. Mater. Res., v.3, pp.1–42.

    Google Scholar 

  • Tirel, C., Brun, J.-P. and Burov, E. (2008) Dynamics and structural development of metamorphic core complexes. Jour. Geophy. Res., v.113, B04403, 25p.

    Article  Google Scholar 

  • Tsunogae, T. and Santosh, M. (2010) Ultrahigh-temperature metamorphism and decompression history of sapphirine granulites from Rajapalaiyam, southern India: implications for the formation of hot orogens during Gondwana assembly. Geol. Mag., v.147, pp.42–58.

    Article  Google Scholar 

  • Veblen, D.R. and Ferry, J.M. (1983) A TEM study of the biotitechlorite reaction and comparison with petrologic observation. Am. Mineral., v.68, pp.1160–1168

    Google Scholar 

  • White, R.W. and Powell, R. (2002) Melt loss and the preservation of granulites facies mineral assemblages. Jour. Metamorph. Geol., v.20, pp.621–632.

    Google Scholar 

  • White, R.W., Powell, R. and Holland, T.J.B. (2001) Calculation of partial melting equilibria in the system Na2O-CaO-K2OFeO-MgO-Al2O3-SiO2-H2O (NCKFMASH). Jour. Metamorph. Geol., v.19, pp.139–153.

    Article  Google Scholar 

  • White, R.W., Powell, R. and Clarke, G.L. (2002) The interpretation of reaction textures in Fe-rich metapelitic granulites of the Musgrave Block, central Australia: constraints from mineral equilibria calculations in the system K2O-FeO-MgO-Al2O3-SiO2-H2O-TiO2-Fe2O3. Jour. Metamorph. Geol., v.20, pp.41–55.

    Article  Google Scholar 

  • White, R.W., Powell, R. and Holland, T.J.B. (2007) Progress relating to calculation of partial melting equilibria for metapelites. Jour. Metamorph. Geol., v.25, pp.511–527.

    Article  Google Scholar 

  • Whitney, D.L., Teyssier, C. and Fayon, A.K. (2004) Isothermal decompression, partial melting, and the exhumation of deep continental crust. In: J. Grocott, K.J.W. McCaffrey, G. Taylor and B. Tikoff (Eds.), Vertical Coupling and Decoupling in the Lithosphere. Spec. Publ., Geol. Soc., London, v.227, pp.313–326.

    Google Scholar 

  • Whitney, D.L. and Evans, B.W. (2010) Abbreviations for names of rock-forming minerals.Am. Mineral., v.95, pp.185–187.

    Article  Google Scholar 

  • Zen, E.-A. (1995) Crustal magma generation and low-pressure high-temperature regional metamorphism in an extensional environment; possible application to the Lachlan Belt, Australia. Am. Jour. Sci., v.295, pp.851–874.

    Article  Google Scholar 

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Sreejith, C., Ravindra Kumar, G.R. MnNCKFMASH phase relations in cordierite-orthopyroxene migmatitic gneisses, southern india: implications for low-pressure crustal melting under granulite-facies. J Geol Soc India 80, 613–627 (2012). https://doi.org/10.1007/s12594-012-0188-7

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