SUPPLEMENTAL MATERIAL

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Deborah Andrews
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1 SUPPLEMENTAL MATERIAL THERMOBAROMETRIC CALCULATIONS Most compositions were taken directly from published tables. In one instance (Vannay & Graseman 1998), garnet compositions that corresponded most closely to peak metamorphic conditions, as identified using petrologic criteria, were derived from zoning profile plots and used for calculations rather than tabulated rim compositions. Thermobarometric calibrations included Grt-Bt (Ferry & Spear 1978; Berman 1990), Grt-Hbl (Graham & Powell 1984), Grt-Pl-Ms-Bt (Hoisch 1990), Grt-Pl-Alsi-Qtz (Koziol & Newton 1988; Koziol 1989), and Grt-Pl-Hbl-Qtz ( & Spear 1990). These calibrations commonly produce P-T estimates consistent with phase equilibrium constraints. Program Thermobarometry (Spear et al. 1991) was used for all calculations. Unless directly reported, P and T uncertainties were assumed to be ±0.5 kbar (P<10 kbar), ±1 kbar (P 10 kbar), ±35 C (T<800 C), and ±50 C (T 800 C). Raman spectroscopic T s for carbonaceous material (Beyssac et al. 2002) were also included for the Kumaun transect in India, Everest THS, and the Central/Western and Western THS regions of Bhutan (Celerier et al. 2009; Cottle et al. 2011; Kellett & Grujic 2012; Cooper et al. 2013). Ti-in-Zrc temperatures for Sikkim migmatites (Kellett et al. 2013, Rubatto et al. 2013) were calculated assuming a(tio 2 ) = 0.80±0.2 (Chambers & 2012). Note that P-T conditions based on barometers that involve rutile plus ilmenite are sometimes reported, but are seldom accurate because coexisting Rt+Ilm are rarely in equilibrium (<1% of rocks, in my experience; usually Ilm is retrograde after Rt). Numerous pseudosections illustrate the extremely narrow P-T field in which Rt+Ilm stably coexist. One can calculate maximum or minimum pressure limits depending on which oxide was stable at peak conditions (e.g. & Valley 1994), but few studies describe oxide textures sufficiently well to allow this. Mineral composition data sources in Fig. 4 are: Caddick et al. (2007), Catlos et al. (2001), Catlos et al. (2004), Corrie & (2011), Corrie et al. (2012), Daniel et al. (2003), Dasgupta et al. (2009), Davidson et al. (1997), Faak et al. (2012), Goswami et al. (2009), Imayama et al. (2010), Inger & Harris (1992), & Corrie (2011), (2008), et al. (2001), Leger et al. (2013), Martin et al. (2010), Mohan et al. (1989), Neogi et al. (1998), Robyr et al. (2002), Rubatto et al. (2013), Schneider & Masch (1993), Spencer et al. (2012), Stephenson et al. (2000), Vance & Mahar (1998), Vannay & Graseman (1998), Wang et al. (2013), Webb et al. (2011), and Wyss et al. (2000). Spectroscopic data sources in Fig. 4 are: Celerier et al. (2009), Cooper et al. (2013), Cottle et al. (2011), and Kellett & Grujic (2012). 1

2 P-T PATH CALCULATIONS For calculating P-T paths from data in Chambers et al. (2009), I assumed Grt growth in St-absent assemblages (Spear et al. 1990), and correlated Grt and Pl zoning profiles. Two calculations were made, assuming presence vs. absence of paragonite. Pseudosections predict paragonite (Chambers et al. 2009), but it is not reported in these rocks. A P-T condition of 575 C and 8 kbar was assumed for the termination of garnet growth (prior to St-in), and Bt and Chl compositions were calculated based on Fe- Mg-Mn exchange. These paths must underestimate T because they do not account for the formation of higher-grade St and Ky. LEUCOGRANITE ZRC-SATURATION TEMPERATURES Leucogranite compositions were taken from Brouand et al. (1990), Searle et al. (1997), Visona & Lombardo (2002), Zhang et al. (2004), and Singh (2013) 2

3 SUPPLEMENTAL LITERATURE CITED Berman RG Mixing properties of Ca-Mg-Fe-Mn garnets. Am. Mineral. 75: Beyssac O, Goffe B, Chopin C, Rouzaud JN Raman spectra of carbonaceous material in metasediments: a new geothermometer. J. Metamorphic Geol. 20: Brouand M, Banzet G, Barbey P Zircon behavior during crustal anatexis. Evidence from the Tibetan Slab migmatites (Nepal). J. Volcanol. Geotherm. Res. 44: Caddick MJ, Bickle MJ, Harris NBW, Holland TJB, Horstwood MSA, et al Burial and exhumation history of a Lesser Himalayan schist: Recording the formation of an inverted metamorphic sequence in NW India. Earth Planet. Sci. Lett. 264: Catlos EJ, Harrison TM, MJ, Grove M, Ryerson FJ, et al Geochronologic and thermobarometric constraints on the evolution of the Main Central Thrust, central Nepal Himalaya. J. Geophys. Res. 106: Catlos EJ, Dubey CS, Harrison TM, Edwards MA Late Miocene movement within the Himalayan Main Central Thrust shear zone, Sikkim, north-east India. J. Metamorphic Geol. 22: Celerier J, Harrison TM, Beyssac O, Herman F, Dunlap WJ, Webb AAG The Kumaun and Garwhal Lesser Himalaya, India: Part 2. Thermal and deformation histories. Geol. Soc. Am. Bull. 121: Chambers JA, MJ Titanium in muscovite, biotite, and hornblende: Modeling, thermometry and rutile activities in metapelites and amphibolites. Am. Mineral. 97: Chambers J, Caddick M, Argles T, Horstwood M, Sherlock S, et al Empirical constraints on extrusion mechanisms from the upper margin of an exhumed high-grade orogenic core, Sutlej valley, NW India. Tectonophys. 477: Cooper FJ, Hodges KV, Adams BA Metamorphic constraints on the character and displacement of the South Tibetan fault system, central Bhutanese Himalaya. Lithosphere 5: Corrie SL, MJ Metamorphic history of the central Himalaya, Annapurna region, Nepal, and implications for tectonic models. Geol. Soc. Am. Bull. 123: Corrie SL, MJ, McQuarrie N, Long SP Flattening the Bhutan Himalaya. Earth Planet. Sci. Lett : Cottle JM, Waters DJ, Riley D, Beyssac O, Jessup MJ Metamorphic history of the South Tibetan Detachment System, Mt. Everest region, revealed by RSCM thermometry and phase equilibria modelling. J. Metamorphic Geol. 29: Daniel CG, Hollister LS, Parrish RR, Grujic D Exhumation of the Main Central Thrust from lower crustal depths, Eastern Bhutan Himalaya. J. Metamorphic Geol. 21: Dasgupta S, Chakraborty S, Neogi S Petrology of an inverted Barrovian sequence of metapelites in Sikkim Himalaya, India: constraints on the tectonics of inversion. Am. J. Sci. 309: Davidson C, Grujic DE, Hollister LS, Schmid SM Metamorphic reactions related to decompression and synkinematic intrusion of leucogranite, High Himalayan Crystallines, Bhutan. J. Metamorphic Geol. 15: Faak K, Chakraborty S, Dasgupta S Petrology and tectonic significance of metabasite slivers in the Lesser and Higher Himalayan domains of Sikkim, India. J. Metamorphic Geol. 30: Ferry JM, Spear FS Experimental calibration of the partitioning of Fe and Mg between biotite and garnet. Contrib. Mineral. Petrol. 66:

4 Goswami S, Bhowmik SK, Dasgupta S Petrology of a non-classical Barrovian inverted metamorphic sequence from the western Arunachal Himalaya, India. J. Asian Earth Sci. 36: Graham CM, Powell R A garnet-hornblende geothermometer: calibration, testing, and application to the Pelona Schist, Southern California. J. Metamorphic Geol. 2: Hoisch TD Empirical calibration of six geobarometers for the mineral assemblage quartz+muscovite+biotite+plagioclase+garnet. Contrib. Mineral. Petrol. 104: Imayama T, Takeshita T, Arita K Metamorphic P-T profile and P-T path discontinuity across the far-eastern Nepal Himalaya: investigation of channel flow models. J. Metamorphic Geol. 28: Inger S, Harris NBW Tectonothermal evolution of the High Himalayan crystalline sequence, Langtang Valley, northern Nepal. J. Metamorphic Geol. 10: Kellett DA, Grujic D New insight into the South Tibetan detachment system: Not a single progressive deformation. Tectonics 31: doi: /2011tc Kellett DA, Grujic D, Coutand I, Cottle J, Mukul M The South Tibetan detachment system facilitates ultra rapid cooling of granulite-facies rocks in Sikkim Himalaya. Tectonics 32: doi: /tect MJ P-T-t data from central Nepal support critical taper and repudiate large-scale channel flow of the Greater Himalayan Sequence. Geol. Soc. Am. Bull. 120: MJ, Corrie SL Preserved Zr-temperatures and U-Pb ages in high-grade metamorphic titanite: evidence for a static hot channel in the Himalayan orogen. Earth Planet. Sci. Lett. 311: MJ, Spear FS Two new barometers for garnet amphibolites with applications to southeastern Vermont. Am. Mineral. 75: MJ, Valley JW Oxygen isotope constraints on metamorphic fluid flow, Townshend Dam, Vermont, USA. Geochim. Cosmochim. Acta 58: MJ, Catlos EJ, Ryerson FJ, Harrison TM Pressure-temperature-time path discontinuity in the Main Central thrust zone, central Nepal. Geology 29: Koziol AM, Newton RC Redetermination of the anorthite breakdown reaction and improvement of the plagioclase-garnet-al 2 SiO 5 -quartz geobarometer. Am. Mineral. 73: Koziol AM Recalibration of the garnet-plagioclase-al2sio5-quartz (GASP) geobarometer and application to natrual parageneses. EOS Trans. Am. Geophys. Union 70: 493 Leger RM, Webb AAG, Henry DJ, Craig JA, Dubey P Metamorphic field gradients across the Himachal Himalaya, northwest India: Implications for the emplacement of the Himalayan crystalline core. Tectonics 32: doi: /tect Martin AJ, Ganguly J, DeCelles PG Metamorphism of Greater and Lesser Himalayan rocks exposed in the Modi Khola valley, central Nepal. Contrib. Mineral. Petrol. 159: Mohan A, Windley BF, Searle MP Geothermobarometry and development of inverted metamorphism in the Darjeeling Sikkim region of the eastern Himalaya. J. Metamorphic Geol. 7: Neogi S, Dasgupta S, Fukuoka M High P-T polymetamorphism, dehydration melting, and generation of migmatites and granites in the Higher Himalayan Crystalline Complex, Sikkim, India. J. Petrol. 39:

5 Robyr M, Vannay JC, Epard JL, Steck A Thrusting, extension, and doming during the polyphase tectonometamorphic evolution of the High Himalayan Crystalline Zone in NW India. J. Asian Earth Sci. 21: Rubatto D, Chakraborty S, Dasgupta S 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: Schneider C, Masch L The metamorphism of the Tibetan Series from the Manang area, Marsyandi Valley, Central Nepal. Geol. Soc. Special Publ. 74: Searle MP, Parrish RR, Hodges KV, Hurford A, Ayres MW, Whitehouse MJ Shisha Pangma leucogranite, South Tibetan Himalaya; field relations, geochemistry, age, origin, and emplacement. J. Geol. 105: Singh RKB Origin and emplacement of the igher Himalayan leucogranite in the eastern Himalaya: constraints from geochemistry and mineral chemistry. J. Geol. Soc. India 81: Spear FS, MJ, Florence F, Menard T A model for garnet and plagioclase growth in pelitic schists: Implications for thermobarometry and P-T path determinations. J. Metamorphic Geol. 8: Spear FS, Peacock SM, MJ, Florence FP, Menard T Computer programs for petrologic P-T-t path calculations. Am. Mineral. 76: Spencer CJ, Harris RA, Dorais MJ The metamorphism and exhumation of the Himalayan metamorphic core, eastern Garhwal region, India. Tectonics 31: /2010tc Stephenson BJ, Waters DJ, Searle MP Inverted metamorphism and the Main Central thrust: field relations and thermobarometric constraints from the Kishtwar Window, NW Indian Himalaya. J. Metamorphic Geol. 18: Vance D, Mahar E Pressure-temperature paths from P-T pseudosections and zoned garnets: Potential, limitations and examples from the Zanskar Himalaya, NW India. Contrib. Mineral. Petrol. 132: Vannay JC, Grasemann B Inverted metamorphism in the High Himalaya of Himachal Pradesh (NW India): phase equilibria versus thermobarometry. Schweizerische Mineralogische und Petrographische Mitteilungen 78: Visona D, Lombardo B Two-mica and tourmaline leucogranites from the Everest-Makalu region (Nepal-Tibet); Himalayan leucogranite genesis by isobaric heating? Lithos 62: Wang JM, Zhang JJ, Wang XX Structural kinematics, metamorphic P-T profiles and zircon geochronology across the Greater Himalayan Crystalline Complex in south-central Tibet: implication for a revised channel flow. J. Metamorphic Geol. in press Webb AAG, Yin A, Harrison TM, Celerier J, Gehrels GE, et al Cenozoic tectonic history of the Himachal Himalaya (northwestern India) and its constraints on the formation mechanism of the Himalayan orogen. Geosphere 7: Wyss M Metamorphic evolution of the northern Himachal Himalaya: phase equilibria constraints and thermobarometry. Schweizerische Mineralogische und Petrographische Mitteilungen 80: Zhang HF, Harris N, Parrish R, Zhang L, Zhao Z U-Pb ages of Kude and Sajia leucogranites in Saffia dome from North Himalaya and their geological implications. Chin. Sci. Bull. 49:

Thermobarometry of the Leo Pargil Dome, NW India: Insights into Exhumation of Mid-Crustal Rocks in the Himalaya

Pursuit - The Journal of Undergraduate Research at the University of Tennessee Volume 2 Issue 1 Spring 2011 Article 4 March 2011 Thermobarometry of the Leo Pargil Dome, NW India: Insights into Exhumation