Current Science

Open Access Open Access  Restricted Access Subscription Access

Garnetiferous Metamorphic Rocks in Jaspa Granite, Himachal Pradesh, India:Implication of Tethyan Himalayan Metamorphism and Tectonics


Affiliations
1 Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun 248 001, India
 

Studies on the magmatic enclaves, pelitic xenoliths and host Jaspa granite pluton outcropped in the Lahaul area, NW Himalaya, India illustrate that the rocks have undergone garnet-grade metamorphism. The P -T pseudosection modelling shows that the metamorphic mineral assemblage is stable in the P -T range ~4.5-7.3 kbar and ~440-500°C, matching quite well with the results obtained from the conventional geothermobarometers (5.7-8.6 kbar and 409-531°C). The observed garnet-grade metamorphism in and around the Jaspa pluton is proposed to be due to localized perturbation of high-temperature isotherms in the Tethys Himalaya, as a consequence of the Cenozoic tectono-thermal event during Himalayan orogeny. Further, the Haimanta group of Tethys Himalayan rocks in the Lahaul area has been interpreted to have attained right-way-up metamorphic field gradient.

Keywords

Garnet-Grade Metamorphism, Granite Pluton, Magmatic Enclaves, Pelitic Xenoliths.
User
Notifications
Font Size

  • Gansser, A., The Geology o f the Himalaya, Wiley Inter-science, New York, 1964.

  • LeFort, P., Himalayas: the collided range. Present knowledge of the continental arc. Am. J. Sci., 1975, 275A, 1-44.

  • Steck, A. et al., Geological transect across the Northwestern Himalaya in eastern Ladakh and Lahul (a model for the continental collision of India and Asia). Eclogae Geol. Helv., 1993, 86, 219-263.

  • Robyr, M., Hacker, B. R. and Mattinson, J. M., Doming in compressional orogenic settings: new geochronological constraints from the NW Himalaya. Tectonics, 2006, 25, TC2007; doi:10.1029/2004TC001774.

  • Yin, A., Cenozoic tectonic evolution of the Himalayan orogen as constrained by along strike variation of structural geometry, exhumation history, and foreland sedimentation. Earth Sci. Rev., 2006, 76, 1-131.

  • De'zes, P. J., Vannay, J. C., Steck, A., Bussy, F. and Cosca, M., Synorogenic extension: quantitative constraints on the age and displacement of the Zanskar shear zone (northwest Himalaya). Geol. Soc. Am. Bull., 1999, 111, 364-374.

  • Walker, J. D., Martin, M. W., Bowring, S. A., Searle, M. P., Waters, D. J. and Hodges, K. V., Metamorphism, melting, and extension: age constraints from the High Himalayan Slab of southeast Zanskar and northwest Lahul. J. Geol., 1999, 107, 473-495.

  • Thakur, S. S. and Tripathi, K., Regional metamorphism in the Haimanta Group of rocks, Sutlej river valley, NW Himalaya. Curr. Sci., 2008, 95, 104-109.

  • Chambers, J. et al., Empirical constraints on extrusion mechanisms from the upper margin of an exhumed high-grade orogenic core, Sutlej valley, NW India. Tectonophysics, 2009, 477, 77-92.

  • Webb, A. A. G., Yin, A., Harrison, T. M., Celerier, J., Gehrels, G. E., Manning, C. E. and Grove, M., Cenozoic tectonic history of the Himachal Himalaya (northwestern India) and its constraints on the formation mechanism of the Himalayan orogen. Geosphere, 2011, 7, 1013-1061.

  • Leger, R. M., Webb, A. A. G., Henry, D. J., Craig, J. A. and Dubey, P., Metamorphic field gradients across the Himachal Himalaya, northwest India: implications for the emplacement of the Himalayan crystalline core. Tectonics, 2013, 32, doi:10.1002/ tect.20020.

  • Pognante, U., Castelli, D., Benna, P., Genovese, G., Oberli, F., Meier, M. and Tonarini, S., The crystalline units of the High Himalayas in the Lahul-Zanskar region (northwest India): metamorphictectonic history and geochronology of the collided and imbricated India plate. Geol. Mag., 1990, 127, 101-116.

  • Thakur, V. C., Tectonics of the central crystallines of western Himalaya. Tectonophysics, 1980, 62, 141-154.

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

  • Connolly, J. A. D., Multivariable phase diagram: an algorithm based on generalized thermodynamics. Am. J. Sci., 1990, 290, 666-718.

  • Connolly, J. A. D., Computation of phase equilibria by linear programming: a tool from geodynamic modelling and its application to subduction zone decarbonation. Earth Planet. Sci. Lett., 2005, 236, 524-541.

  • Holland, T. J. B. and Powell, R., An internally consistent thermodynamic dataset for phases of petrological interest. J. Metamorph. Geol., 1998, 16, 309-344.

  • Marquer, D., Chawla, H. S. and Challandes, N., Pre-alpine highgrade metamorphism in high Himalaya crystalline sequences: evidence from Lower Palaeozoic Kinnaur Kailash Granite and surrounding rocks in Sutlej Valley (Himachal Pradesh, India). Eclogae Geol. He lv, 2000, 93, 207-220.

  • Gehrels, G. E., DeCelles, P. G., Martin, A., Ojha, T. P. and Pinhassi, G., Initiation of the Himalayan orogen as an early Palaeozoic thin-skinned thrust belt. GSA Today, 2003, 13, 4-9.

  • Thakur, S. S., Retrograde corona texture in pre-Himalayan metamorphic mafic xenoliths, Sutlej valley, NW Himalaya: implication on rare occurrence of high-grade rocks in the Himalaya. J. Asian Earth Sci., 2014, 88, 41-49.

  • Thakur, S. S. and Patel, S. C., Mafic and pelitic xenoliths in the Kinnaur Kailash Granite, Baspa river valley, NW Himalaya: evidence of pre-Himalayan granulite metamorphism followed by cooling event. J. Asian Earth Sci., 2012, 56, 105-117.

  • Rameshwar Rao, D. and Sharma, K. K., Petrological and geochemical constraints on the petrogenesis of the Jaspa granite pluton, Lahual region, NW Himalaya. J. Geol. Soc. India, 1995, 45, 629-642.

  • Rameshwar Rao, D. and Gururajan, N. S., Metamorphism of the inverted sequence in Himachal Himalaya: a study from the KulluRohtang-Khoskar section. J. Geol. Soc. India, 2000, 56, 633-649.

  • Sandiford, M., Martin, N., Zhou, S. and Fraser, G., Mechanical consequences of granite emplacement during high-T, low-P metamorphism and the origin of ‘anticlockwise’ P T paths. Earth Planet. Sci. Lett., 1991, 107, 164-172.

  • Sandiford, M. and Powell, R., Some remarks on hightemperaturelow-pressure metamorphism in convergent orogens. J. Metamorph. Geol., 1991, 9, 333-340.

  • Srikantia, S. V. and Bhargava, O. N., The Tandi Group o f Lahaul: its geology and relationship with the Central Himalayan gneiss. J. Geol. Soc. India, 1979, 20, 531-539.

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

  • Hodges, K. V. and Spear, F. S., Geothermometry, geobarometry and the Al2SiO5 triple point at Mt. Moosilauke, New Hampshire. Am. Mineral., 1982, 67, 1118-1134.

  • Perchuk, L. L. and Lavrent’eva, I. V., 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, 1983, pp. 199-239.

  • Ganguly, J. and Saxena, S. K., Mixing properties of aluminosilicate garnets. Constraints from natural and experimental data and applications to geothermobarometry. Am. Mineral., 1984, 69, 88-97.

  • Ghent, E. D. and Stout, M. Z., Geobarometry and geothermometry of plagioclase-biotite-garnet-muscovite assemblages. Contrib. Mineral. Petrol., 1981, 76, 92-97.

  • Hodges, K. V. and Crowley, P. D., Error estimation and empirical geothermometry for pelitic system. Am. Mineral., 1985, 70, 702709.


Abstract Views: 336

PDF Views: 127




  • Garnetiferous Metamorphic Rocks in Jaspa Granite, Himachal Pradesh, India:Implication of Tethyan Himalayan Metamorphism and Tectonics

Abstract Views: 336  |  PDF Views: 127

Authors

S. S. Thakur
Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun 248 001, India
A. K. Singh
Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun 248 001, India
D. Rameshwar Rao
Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun 248 001, India
Rajesh Sharma
Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun 248 001, India
Subhajit Pandey
Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun 248 001, India
Aliba Ao
Wadia Institute of Himalayan Geology, 33 GMS Road, Dehradun 248 001, India

Abstract


Studies on the magmatic enclaves, pelitic xenoliths and host Jaspa granite pluton outcropped in the Lahaul area, NW Himalaya, India illustrate that the rocks have undergone garnet-grade metamorphism. The P -T pseudosection modelling shows that the metamorphic mineral assemblage is stable in the P -T range ~4.5-7.3 kbar and ~440-500°C, matching quite well with the results obtained from the conventional geothermobarometers (5.7-8.6 kbar and 409-531°C). The observed garnet-grade metamorphism in and around the Jaspa pluton is proposed to be due to localized perturbation of high-temperature isotherms in the Tethys Himalaya, as a consequence of the Cenozoic tectono-thermal event during Himalayan orogeny. Further, the Haimanta group of Tethys Himalayan rocks in the Lahaul area has been interpreted to have attained right-way-up metamorphic field gradient.

Keywords


Garnet-Grade Metamorphism, Granite Pluton, Magmatic Enclaves, Pelitic Xenoliths.

References





DOI: https://doi.org/10.18520/cs%2Fv115%2Fi8%2F1576-1583