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

详细信息    查看全文

• 作者：Divya Prakash ; Suparna Tewari
• 关键词：Garnet ; sillimanite gneiss ; textural relationship ; pseudosection ; P–T conditions ; Darjeeling ; Eastern Himalaya
• 刊名：Journal of Earth System Science
• 出版年：2015
• 出版时间：August 2015
• 年：2015
• 卷：124
• 期：6
• 页码：1187-1199
• 全文大小：3,633 KB
• 参考文献：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. 243-69.
  Auden J B 1935 Traverses in Himalaya; Rec. Geol. Surv. India 69(2) 161-67.
  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 1-4.
  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 142 199-22.
  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 45-22.
  Berman R G 1990 Mixing properties of Ca–Mg–Fe–Mn garnets; Am. Mineral. 75 328-44.
  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 87-3.
  Bose P N 1891 Notes of the geological and mineral resources of Sikkim; Rec. Geol. Surv. India 26(24) 217-30.
  Carmichael D M 1970 Intersecting isograds in the Whetstone lake area, Ontario; J. Petrol. 11 147-81.
  Chakraborty K R and Sen S K 1967 Regional metamorphism of pelitic rocks around Kandra Singhbhum Bihar; Contrib. Mineral. Petrol. 16 210-32.
  Chinner G A 1961 The origin of sillimanite in Glen Clova, Angus; J. Petrol. 2 312-23.
  Coggon R and Holland T J B 2002 Mixing properties of phengitic micas and revised garnet-phengite thermobarometers; J. Metamor. Geol. 20 683-96.
  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. 236 524-41.
  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 1-9.
  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. 109 130-37.
  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 43-4.
  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 24-9.
  Froese E and Gasparrini E 1975 Metamorphic zones in the Snow Lake area, Manitoba; Can. Miner. 13 162-67.
  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. 277 750-67.
  Green N L and Usdansky S I 1986 Ternary-feldspar mixing relations and thermobarometry; Am. Mineral. 71 1100-108.
  Guidotti C V 1974 Transition from staurolite to sillimanite zone, Rangeley Quadrangle, Maine; Bull. Geol. Soc. Am. 85 475-90.
  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 75 313-22.
  Heim A and Gansser A 1939 Central Himalaya, geological observations of the Swiss expedition; Memoir Soc. Helv. Sci. Nat. 73(1) 1-45.
  Hodges K V and Crowley P D 1985 Error estimation and empirical geothermobarometry for pelitic systems; Am. Mineral. 70 702-09.
  Hoisch T D 1990 Empirical calibration of six geobarometers for the mineral assemblage quartz + muscovite + biotite + plagioclase + garnet; Contrib. Mineral. Petrol. 104 225-34.
  Holland T J B and Powell R 1998 An internally consistent thermodynamic data set for phases of petrological interest; J. Metamor. Geol. 16 309-43.
  Holland T and Powell R 2001 Calculation of phase relations involving haplogranitic melts using an internally consistent thermodynamic dataset; J. Petrol. 42 673-83.
  Holland T and Powell R 2003 Activity-composition relations for phases in petrological calculations: An asymmetric multicomponent formulation; Contrib. Mineral. Petrol. 145 492-01.
  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. 10 395-06.
  Hollister L S 1969 Contact metamorphism in Kwoiek area, British Columbia: An end member of the metamorphic process
• 作者单位：Divya Prakash (1)
  Suparna Tewari (1)
  
  1. Centre of Advanced Study in Geology, Banaras Hindu University, Varanasi, 221 005, India
  
• 刊物类别：Earth and Environmental Science
• 刊物主题：Earth sciences
  Geosciences
  Extraterrestrial Physics and Space Sciences
  
• 出版者：Springer India
• ISSN：0973-774X

文摘

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±30?/sup>C. The observation in this study has important bearing on the inverted metamorphism in the Himalayan metamorphic belt. Keywords Garnet-sillimanite gneiss textural relationship pseudosection P–T conditions Darjeeling Eastern Himalaya