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Garnet-sillimanite bearing gneisses from Darjeeling, eastern Himalaya: Textural relationship and P–T conditions


The area around Darjeeling consists of medium grade metamorphic rocks and provides a classic example of inverted Himalayan metamorphism. The area under investigation shows upper amphibolite facies metamorphism (sillimanite-muscovite subfacies), rocks are intimately associated with the migmatites and granites. The presence of quartzite, calc-silicate rocks, graphitic schist and abundance of aluminous minerals like kyanite or sillimanite in these rocks indicate their metasedimentary character. Granet-sillimanite bearing gneisses occupy most of the area of Darjeeling but not persistent throughout. Textural relationship suggests sequential growth of progressively higher-grade metamorphic minerals during D 1 and D 2 deformation. The relative X Mg in the minerals varies in the order: biotite >staurolite> garnet, and the X Mn decreases in the order: garnet >staurolite>biotite. The P–T evolution of these garnet-sillimanite gneiss has been constrained through the use of conventional geothermobarometry, internally consistent TWEEQU programme and Perple_X software in the KFMASH model system, the combination of these three approaches demonstrates that the Darjeeling gneisses experienced peak pressure and temperature at 7.0±0.3 kbar and 700±30C. The observation in this study has important bearing on the inverted metamorphism in the Himalayan metamorphic belt.

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  • Acharya S K 1978 Stratigraphy and tectonic features of eastern Himalaya; In: Tectonic Geology of the Himalaya (ed.) Saklani P S (Delhi: Today and Tomorrow’s Publishers), pp. 243–269.

  • Auden J B 1935 Traverses in Himalaya; Rec. Geol. Surv. India 69(2) 161–167.

  • Auzanneau E, Schmidt M W, Vielzeuf D and Connolly J A D 2010 Titanium in phengite: A geobarometer for high temperature eclogites; Contrib. Mineral. Petrol. 159 1–24.

  • Banerjee H and Bhattacharya P K 1981 Concurrent granitization under different metamorphic facies conditions in the lesser Himalayas of the Sikkim–Darjeeling region; Neues Jahrbuch fur Mineral. Abhandlungen 142 199–222.

  • Basu S K 2013 Geology of Sikkim State and Darjeeling District of West Bengal; Geol. Soc. India 356.

  • Berman R G 1988 Internally consistent thermodynamic data for stoichiometric minerals in the system Na2O–K2O–CaO–Al2O3–SiO2–TiO2–H2O–CO2; J. Petrol. 29 45–522.

  • Berman R G 1990 Mixing properties of Ca–Mg–Fe–Mn garnets; Am. Mineral. 75 328–344.

  • Bhattacharya A, Mohanty L, Maji A, Sen S K and Raith M 1992 Non-ideal mixing in the phlogophite-annite binary: Constraints from experimental data on Mg–Fe partitioning and a reformulation of the biotite-garnet geothermometers; Contrib. Mineral. Petrol. 111 87–93.

  • Bose P N 1891 Notes of the geological and mineral resources of Sikkim; Rec. Geol. Surv. India 26(24) 217–230.

  • Carmichael D M 1970 Intersecting isograds in the Whetstone lake area, Ontario; J. Petrol. 11 147–181.

  • Chakraborty K R and Sen S K 1967 Regional metamorphism of pelitic rocks around Kandra Singhbhum Bihar; Contrib. Mineral. Petrol. 16 210–232.

  • Chinner G A 1961 The origin of sillimanite in Glen Clova, Angus; J. Petrol. 2 312–323.

  • Coggon R and Holland T J B 2002 Mixing properties of phengitic micas and revised garnet-phengite thermobarometers; J. Metamor. Geol. 20 683–696.

  • Connolly J A D 2005 Computation of phase equilibria by linear programming: A toll for geodynamic modeling and its application to subduction zone decarbonation; Earth Planet. Sci. Lett. 236 524–541.

  • Crawford M B and Windley B F 1990 Leucogranites of Himalaya/Karakoram: Implications for migmatitic evolution within collisional belts and study of collision related leucogranite petrogenesis; J. Volcano. Geotherm. Res. 44 1–19.

  • Dasgupta S, Sengupata P, Guha D and Fukuoka D 1991 A refined garnet-biotite Fe–Mg exchange geothermometer and its application in amphibolites and granulites; Contrib. Mineral. Petrol. 109 130–137.

  • Dasgupta S, Chakraborty S and Neogi S 2009 Petrology of an inverted Barrovian sequence of metapelites in Sikkim Himalaya, India: Constraints on the tectonic inversion; Am. J. Sci. 309 43–84.

  • Deer W A, Howie P A and Zussman J 1962 Rock-forming minerals; Longmann, London 1 and 3.

  • Foster M D 1960 Interpretation of the composition of trioctahedral micas; US Geol. Surv. Prof. Paper 354-B 24–49.

  • Froese E and Gasparrini E 1975 Metamorphic zones in the Snow Lake area, Manitoba; Can. Miner. 13 162–167.

  • Gansser A 1964 Geology of the Himalayas; Innterscience Publ., Wiley, New York, 289p.

  • Goldman D S and Albee A L 1977 Correlation of Mg/Fe partitioning between garnet and biotite with partitioning between quartz and magnetite; Am. J. Sci. 277 750–767.

  • Green N L and Usdansky S I 1986 Ternary-feldspar mixing relations and thermobarometry; Am. Mineral. 71 1100–1108.

  • Guidotti C V 1974 Transition from staurolite to sillimanite zone, Rangeley Quadrangle, Maine; Bull. Geol. Soc. Am. 85 475–490.

  • Gupta S, Das A, Goswami S, Modak A and Mondal S 2010 Evidence for structural discordance in the inverted metamorphic sequence of Sikkim Himalaya: Towards resolving the Main Central Thrust controversy; J. Geol. Soc. India 75 313–322.

  • Heim A and Gansser A 1939 Central Himalaya, geological observations of the Swiss expedition; Memoir Soc. Helv. Sci. Nat. 73(1) 1–245.

  • Hodges K V and Crowley P D 1985 Error estimation and empirical geothermobarometry for pelitic systems; Am. Mineral. 70 702–709.

  • Hoisch T D 1990 Empirical calibration of six geobarometers for the mineral assemblage quartz + muscovite + biotite + plagioclase + garnet; Contrib. Mineral. Petrol. 104 225–234.

  • Holland T J B and Powell R 1998 An internally consistent thermodynamic data set for phases of petrological interest; J. Metamor. Geol. 16 309–343.

  • Holland T and Powell R 2001 Calculation of phase relations involving haplogranitic melts using an internally consistent thermodynamic dataset; J. Petrol. 42 673–683.

  • Holland T and Powell R 2003 Activity-composition relations for phases in petrological calculations: An asymmetric multicomponent formulation; Contrib. Mineral. Petrol. 145 492–501.

  • Holland T, Baker J and Powell R 1998 Mixing properties and activity-composition relationships of chlorites in the system MgO–FeO–Al2O3–SiO2–H2O; Euro. J. Mineral. 10 395–406.

  • Hollister L S 1969 Contact metamorphism in Kwoiek area, British Columbia: An end member of the metamorphic process; Geol. Soc. Am. Bull. 80 2465–2494.

  • Indares A and Martignole J 1985 Biotite-garnet thermometry in the granulite facies: The influence of Ti and Al in biotite; Am. Mineral. 70 272–278.

  • Jangpangi B S 1972 Some observations on the stratigraphy and reverse metamorphism in Darjeeling Hills; Him. Geol. 2 356–370.

  • Koziol A M 1989 Recalibration ofgarnet-plagioclase-Al2SiO5- quartz (GASP) geobarometer and applications to natural parageneses; EOS (Trans. Am. Geophys. Union) 70 493.

  • Koziol A M and Newton R C 1988 Redetermination of the anorthite breakdown and improvement of the plagioclase-garnet-Al 2SiO 5-quartz geobarometer; Am. Mineral. 73 216–223.

  • Lal R K and Ackermand D 1979 Coexisting chloritoid-staurolite from the sillimanite (fibrolite) zone, Sini, district Singhbhum, India; Lithos 12 133–142.

  • Lal R K and Singh J B 1978 Prograde polyphase regional metamorphism and metamorphic reactions in pelitic schists at Sini, district Sighbhum India; N. jb. Miner. Abh. 131 304–333.

  • Lal R K, Mukerji S and Ackermand D 2005 Barrovian metamorphism of Takdah, Darjeeling (eastern Himalaya); In: Himalaya: Geological aspects (ed.) Saklani P S, 2 529–573.

  • Le Fort P, Cuney M, Daniel C, France Lanord C, Sheppard S M F, Upreti B N and Videl P 1987 Crustal generation of the Himalayan leucogranites; Tectonophys. 134 39–57.

  • Mallet F R 1875 On the geology and mineral resources of the Darjeeling district and the western Duars; Geol. Surv. India Memoir 11(I) 1–50.

  • Mohan A, Windley B F and Searle M P 1989 Geothermobarometry and development of inverted metamorphism in the Darjeeling–Sikkim region of the Eastern Himalaya ; J. Metamor. Geol. 1 95–110.

  • Mukhopadhyay M K and Gangopadhyay P K 1971 Structural characteristics of rocks around Kalimpong, West Bengal; Him. Geol. 1 213–230.

  • Mukul M 2000 The geometry and kinematics of the Main Boundary Thrust and related neotectonics in the Darjiling Himalayan fold-and-thrust belt, West Bengal, India; J. Struct. Geol. 22 1261–1283.

  • Newton R C and Haselton H T 1981 Thermodynamics of the garnet-plagioclase-Al 2SiO 5-quartz geobarometers; In: Thermodynamics of minerals and melts (eds) Newton R C, Navrotsky A and Wood B J, Adv. Phys. Geochem. (New York: Springer Verlag) 2 129–145.

  • Perchuk L L 1990 Derivation of thermodynamically consistent system of geothermometers and geobarometers for metamorphic rocks and magmatic rocks; In: Progress in metamorphic and magmatic petrology (ed.) Perchuk L L, Cambridge University Press, pp. 93–112.

  • Perchuk L L and Lavrent’eva I V 1983 Experimental investigation of exchange equilibria in the system cordierite-garnet-biotite; In: Kinetics and equilibrium in mineral reactions (ed.) Saxena S K, Springer-Verlag, New York, pp. 199–239.

  • Perchuk L L, Aranovich L Y, Podlesskii K K, Lavrent’eva I V, Gerasimov V Y, Fed’Kin V V, Kitsul V I, Karasakov L P and Berdnikov N V 1985 Precambrian granulites of the Aldan shield, eastern Siberia, USSR; J. Metamor. Geol. 3(3) 265–310.

  • Powell R and Holland T 1999 Relating formulations of the thermodynamics of mineral solid solutions: Activity modeling of pyroxenes, amphiboles, and micas; Am. Mineral. 84 1–14.

  • Prakash D and Tewari S 2013 Field and textural relationship in pelitic schists and gneisses from the area around Mangpu, Darjeeling district, West Bengal; J. Geol. Soc. India 81 451–454.

  • Ray S 1947 Zonal metamorphism in Eastern Himalaya and some aspects of local geology; Quart. J. Min. Met. Soc. India 19 117–139.

  • Rubatto D, Chakraborty S and Dasgupta S 2013 Timescales of crustal melting in the Higher Himalayan crystallines (Sikkim, Eastern Himalaya) inferred from trace element- constrained monazite and zircon chronology; Contrib. Mineral. Petrol. 165 349–372.

  • Schreyer W, Abraham K and Behr H J 1975 Sapphirine and associated minerals from the kornerupine rocks and Waldheim, Saxony; N. ZJb. Miner. Abh. 126 1–27.

  • Sinha Roy S 1974 Polymetamorphism in Daling rocks from a part of Eastern Himalaya and some problems of Himalayan metamorphism; Him. Geol. 4 47–101.

  • Spear F S, Kohn M J and Cheney J T 1999 P–T paths from anatectic pelites; Contrib. Mineral. Petrol. 134 17–32.

  • Thompson A B 1974 Calculation of muscovite-paragonite-alkali feldspar phase relation; Contrib. Mineral. Petrol. 44 173–194.

  • Thompson A B 1976 Mineral reaction in pelitic rocks: I. Prediction of P–T–X (Fe–Mg) phase relations. II. Calculation of some P–T–X (Fe–Mg) phase relations; Am. J. Sci. 276 401–454.

  • Thompson J B and Norton S A 1968 Palaeozoic regional metamorphism in New England and adjacent areas; In: Studies of Appalachian Geology: Northern and Maritime (eds) E-an-Zen, White W S, Hadley J B and Thompson J B Jr, Intersci. Wiley, New York, pp. 319– 327.

  • Tracy R J 1978 High grade metamorphic reactions and partial melting in pelitic schist, west-central Massachusetts; Am. J. Sci. 278 150–178.

  • Tracy R J, Robinson P and Thompson A B 1976 Garnet composition and zoning in the determination of temperature and pressure of metamorphism, central Massachusetts; Am. Mineral. 61 762–775.

  • Turner F J 1968 Metamorphic Petrology; McGraw-Hill Book Co., New York.

  • Turner F J and Verhoogen J 1960 Igneous and Metamorphic Petrology, 2nd edn; McGraw-Hill Book Co., New York.

  • Wager L R 1939 The Lachi Series of North Sikkim and the age of the rocks forming the Mt. Everest; Rec. Geol. Surv. India 74 171–188.

  • White R W, Powell R, Holland T J B and Worley B A 2000 The effect of TiO2 and Fe2O3 on metapelitic assemblages at greenschist and amphibolite facies conditions: Mineral equilibria calculations in the system K2O–FeO–MgO–Al2O3–SiO2–H2O–TiO2–Fe2O3; J. Metamor. Geol. 18 497–511.

  • White R W, Powell R and Clarke G L 2003 Prograde metamorphic assemblage evolution during partial melting of metasedimentary rocks at low pressures: Migmatites from Mt Stafford, central Australia; J. Metamor. Geol. 44(11) 1937–1960.

  • Winkler H G F 1978 Petrogenesis of metamorphic rocks; Springer Verlag, New York, 334p.

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Authors thank the Head, Department of Geology, Banaras Hindu University and the CAS programme of the UGC at BHU for providing necessary infrastructural facilities. They also thank anonymous reviewers for the constructive comments that led to substantial improvement in the manuscript and deeply appreciate the editorial efficiency of Prof. M Jayananda.

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Correspondence to Divya Prakash.

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Prakash, D., Tewari, S. Garnet-sillimanite bearing gneisses from Darjeeling, eastern Himalaya: Textural relationship and P–T conditions. J Earth Syst Sci 124, 1187–1199 (2015).

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  • Garnet-sillimanite gneiss
  • textural relationship
  • pseudosection
  • P–T conditions
  • Darjeeling
  • Eastern Himalaya