Skip to main content
Log in

Timescales of partial melting in the Himalayan middle crust: insight from the Leo Pargil dome, northwest India

  • Original Paper
  • Published:
Contributions to Mineralogy and Petrology Aims and scope Submit manuscript

Abstract

The Leo Pargil dome (LPD) in northwest India exposes an interconnected network of pre-, syn-, and post-kinematic leucogranite dikes and sills that pervasively intrude amphibolite-facies metapelites of the mid-crustal Greater Himalayan sequence. Leucogranite bodies range from thin (5-cm-wide) locally derived sills to thick (2-m-wide) crosscutting dikes extending at least 100 m. Three-dimensional exposures elucidate crosscutting relations between different phases of melt injection and crystallization. Combined laser ablation inductively coupled plasma mass spectrometry U–Th/Pb geochronology and trace element analysis on well-characterized monazite grains from nineteen representative leucogranites yields a large, internally consistent data set of approximately 700 U–Th/Pb and 400 trace element analyses. Grain-scale variations in age correlate with trace element distributions and indicate semi-continuous crystallization of monazite from 30 to 18 Ma. The youngest U–Th/Pb ages in a given sample are consistent with the outcrop-scale crosscutting relations, whereas older ages within individual samples record inheritance from partially crystallized melt and source metapelites. U–Th/Pb isotopic and trace element data are incorporated into a model of melting within the LPD that involves (1) steady-state equilibrium batch melting of compositionally homogeneous metapelitic sources; (2) pulses of increased melt mobility lasting 1–2 m.y. resulting in segregation of melt from its source and amalgamation into mixed magmas; and (3) rapid emplacement and final crystallization of leucogranite bodies. Melt systems in the LPD evolved from locally derived, in situ melt in migmatitic source rocks into a vast network of dikes and sills in the overlying non-migmatitic host rocks.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9

Similar content being viewed by others

References

  • Aleinikoff JN, Schenck WS, Plank MO et al (2006) Deciphering igneous and metamorphic events in high-grade rocks of the Wilmington Complex, Delaware: morphology, cathodoluminescence and backscattered electron zoning, and SHRIMP U–Pb geochronology of zircon and monazite. Geol Soc Am Bull 118:39–64. doi:10.1130/B25659.1

    Article  Google Scholar 

  • Aoya M, Wallis SR, Terada K et al (2005) North-south extension in the Tibetan crust triggered by granite emplacement. Geology 33:853. doi:10.1130/G21806.1

    Article  Google Scholar 

  • Beaumont C (2004) Crustal channel flows: 1. Numerical models with applications to the tectonics of the Himalayan–Tibetan orogen. J Geophys Res 109:1–29. doi:10.1029/2003JB002809

    Article  Google Scholar 

  • Beaumont C, Jamieson R (2010) Himalayan Tibetan orogeny: Channel flow versus (critical) wedge models, a false dichotomy. In: Leech ML, Klemperer SL, Mooney WD (eds) Proceedings for the 25th Himalaya–Karakoram–Tibet Workshop: U.S. Geological Survey, Open File Report 2010-1099, pp 25–26

  • Bollinger L, Henry P, Avouac J (2006) Mountain building in the Nepal Himalaya: thermal and kinematic model. Earth Planet Sci Lett 244:58–71. doi:10.1016/j.epsl.2006.01.045

    Article  Google Scholar 

  • Brown M (2001) Orogeny, migmatites and leucogranites: a review. J Earth Syst Sci 110:313–336. doi:10.1007/BF02702898

    Article  Google Scholar 

  • Brown M (2004) The mechanism of melt extraction from lower continental crust of orogens. Trans R Soc Edinb Earth Sci. doi:10.1017/S0263593300000900

  • Brown M, Solar G (1998) Shear-zone systems and melts: feedback relations and self-organization in orogenic belts. J Struct Geol 20:211–227

    Article  Google Scholar 

  • Brown M, Solar GS (1999) The mechanism of ascent and emplacement of granite magma during transpression: a syntectonic granite paradigm. Tectonophysics 312:1–33. doi:10.1016/S0040-1951(99)00169-9

    Article  Google Scholar 

  • Brown M, Averkin YA, McLellan EL, Sawyer EW (1995) Melt segregation in migmatites. J Geophys Res 100:15655. doi:10.1029/95JB00517

    Article  Google Scholar 

  • Brown L, Zhao W, Nelson K et al (1996) Bright spots, structure, and magmatism in southern Tibet from INDEPTH seismic reflection profiling. Science 274:1688–1690

    Article  Google Scholar 

  • Chambers J, Caddick M, Argles T et al (2009) Empirical constraints on extrusion mechanisms from the upper margin of an exhumed high-grade orogenic core, Sutlej valley, NW India. Tectonophysics 477:77–92. doi:10.1016/j.tecto.2008.10.013

    Article  Google Scholar 

  • Chen L, Booker J, Jones A et al (1996) Electrically conductive crust in southern Tibet from INDEPTH magnetotelluric surveying. Science 274:1694–1696

    Article  Google Scholar 

  • Cherniak DJ, Pyle JM (2008) Th diffusion in monazite. Chem Geol 256:52–61. doi:10.1016/j.chemgeo.2008.07.024

    Article  Google Scholar 

  • Cherniak DJ, Watson EB, Grove M, Harrison TM (2004) Pb diffusion in monazite: a combined RBS/SIMS study. Geochim Cosmochim Acta 68:829–840. doi:10.1016/j.gca.2003.07.012

    Article  Google Scholar 

  • Clemens JD, Vielzeuf D (1987) Constraints on melting and magma production in the crust. Earth Planet Sci Lett 86:287–306. doi:10.1016/0012-821X(87)90227-5

    Article  Google Scholar 

  • Cocherie A, Legendre O, Peucat J, Kouamelan A (1998) Geochronology of polygenetic monazites constrained by in situ electron microprobe Th–U-total lead determination: implications for lead behaviour in monazite. Geochim Cosmochim Acta 62:2475–2497

    Article  Google Scholar 

  • Collins WJ, Williams IS (1995) SHRIMP ionprobe dating of short-lived Proterozoic tectonic cycles in the northern Arunta Inlier, central Australia. Precambr Res 71:69–89

    Article  Google Scholar 

  • Copeland P, Parrish R, Harrison T (1988) Identification of inherited radiogenic Pb in monazite and its implications for U-Pb systematics. Nature 333:760–763

    Article  Google Scholar 

  • Copeland P, Mark Harrison T, Le Fort P (1990) Age and cooling history of the Manaslu granite: implications for Himalayan tectonics. J Volcanol Geoth Res 44:33–50. doi:10.1016/0377-0273(90)90010-D

    Article  Google Scholar 

  • Corrie SL, Kohn MJ (2008) Trace-element distributions in silicates during prograde metamorphic reactions: implications for monazite formation. J Metamorph Geol 26:451–464. doi:10.1111/j.1525-1314.2008.00769.x

    Article  Google Scholar 

  • Cottle JM, Jessup MJ, Newell DL et al (2007) Structural insights into the early stages of exhumation along an orogen-scale detachment: the South Tibetan Detachment System, Dzakaa Chu section, Eastern Himalaya. J Struct Geol 29:1781–1797. doi:10.1016/j.jsg.2007.08.007

    Article  Google Scholar 

  • Cottle J, Searle M, Horstwood M, Waters D (2009a) Timing of midcrustal metamorphism, melting, and deformation in the Mount Everest region of southern Tibet revealed by U–(Th)–Pb geochronology. J Geol 117:643–664. doi:10.1086/605994

    Article  Google Scholar 

  • Cottle JM, Jessup MJ, Newell DL et al (2009b) Geochronology of granulitized eclogite from the Ama Drime Massif: implications for the tectonic evolution of the South Tibetan Himalaya. Tectonics. doi:10.1029/2008TC002256

    Google Scholar 

  • Cottle JM, Waters DJ, Riley D et al (2011) Metamorphic history of the South Tibetan Detachment System, Mt. Everest region, revealed by RSCM thermometry and phase equilibria modelling. J Metamorph Geol 29:561–582. doi:10.1111/j.1525-1314.2011.00930.x

    Article  Google Scholar 

  • DeCelles PG (2000) Tectonic implications of U–Pb zircon ages of the Himalayan orogenic belt in Nepal. Science 288:497–499. doi:10.1126/science.288.5465.497

    Article  Google Scholar 

  • Deniel C, Vidal P, Fernandez A (1987) Isotopic study of the Manaslu granite (Himalaya, Nepal): inferences on the age and source of Himalayan leucogranites. Contrib Miner Petrol 96:78–92

    Article  Google Scholar 

  • Edwards M, Harrison T (1997) When did the roof collapse? Late Miocene north-south extension in the high Himalaya revealed by Th–Pb monazite dating of the Khula Kangri granite. Geology 25:543–546. doi:10.1130/0091-7613(1997)025<0543

    Article  Google Scholar 

  • Eggins SM, Kinsley LPJ, Shelley JMG (1998) Deposition and element fractionation processes during atmospheric pressure laser sampling for analysis by ICP-MS. Appl Surf Sci 127–129:278–286. doi:10.1016/S0169-4332(97)00643-0

    Article  Google Scholar 

  • Eggins SM, Grün R, McCulloch MT et al (2005) In situ U-series dating by laser-ablation multi-collector ICPMS: new prospects for Quaternary geochronology. Quatern Sci Rev 24:2523–2538. doi:10.1016/j.quascirev.2005.07.006

    Article  Google Scholar 

  • England P, Thompson A (1984) Pressure-temperature-time paths of regional metamorphism I. heat transfer during the evolution of regions of thickened continental crust. J Petrol 25:894–928

    Article  Google Scholar 

  • Foster G, Parrish RR, Horstwood MSA et al (2004) The generation of prograde P–T–t points and paths; a textural, compositional, and chronological study of metamorphic monazite. Earth Planet Sci Lett 228:125–142. doi:10.1016/j.epsl.2004.09.024

    Article  Google Scholar 

  • Friedrich A, Bowring S, Martin M, Hodges K (1999) Short-lived continental magmatic arc at Connemara, western Irish Caledonides: implications for the age of the Grampian orogeny. Geology 27:27–30. doi:10.1130/0091-7613(1999)027<0027

    Article  Google Scholar 

  • Gansser A (1964) Geology of the Himalayas, vol 289. Interscience Publishers, London

  • Girard M, Bussy F (1999) Late Pan-African magmatism in the Himalaya: new geochronological and geochemical data from the Ordovician Tso Morari metagranites (Ladakh, NW India). Schweiz Mineral Petrogr Mitt 79:399–418

    Google Scholar 

  • Harlov DE, Wirth R, Hetherington CJ (2010) Fluid-mediated partial alteration in monazite: the role of coupled dissolution–reprecipitation in element redistribution and mass transfer. Contrib Miner Petrol 162:329–348. doi:10.1007/s00410-010-0599-7

    Article  Google Scholar 

  • Harris N, Massey J (1994) Decompression and anatexis of Himalayan metapelites. Tectonics 13:1537–1546

    Article  Google Scholar 

  • Harris N, Vance D, Ayres M (2000) From sediment to granite: timescales of anatexis in the upper crust. Chem Geol 162:155–167. doi:10.1016/S0009-2541(99)00121-7

    Article  Google Scholar 

  • Harrison TM, McKeegan K, LeFort P (1995) Detection of inherited monazite in the Manaslu leucogranite by 208Pb232Th ion microprobe dating: crystallization age and tectonic implications. Earth Planet Sci Lett 133:271–282

    Article  Google Scholar 

  • Harrison MT, Grove M, McKeegan KD et al (1999) Origin and episodic emplacement of the Manaslu intrusive complex, central Himalaya. J Petrol 40:3–19. doi:10.1093/petroj/40.1.3

    Article  Google Scholar 

  • Hetherington CJ, Harlov DE, Budzyń B (2010) Experimental metasomatism of monazite and xenotime: mineral stability, REE mobility and fluid composition. Miner Petrol 99:165–184. doi:10.1007/s00710-010-0110-1

    Article  Google Scholar 

  • Hintersberger E, Thiede RC, Strecker MR, Hacker BR (2010) East-west extension in the NW Indian Himalaya. Geol Soc Am Bull 122:1499–1515. doi:10.1130/B26589.1

    Article  Google Scholar 

  • Hodges K (2000) Tectonics of the Himalaya and southern Tibet from two perspectives. Geol Soc Am Bull 112:324–350. doi:10.1130/0016-7606(2000)112<324

    Article  Google Scholar 

  • Horstwood MSA, Foster GL, Parrish RR et al (2003) Common-Pb corrected in situ U–Pb accessory mineral geochronology by LA-MC-ICP-MS. J Anal At Spectrom 18:837. doi:10.1039/b304365g

    Article  Google Scholar 

  • Inger S, Harris N (1993) Geochemical constraints on leucogranite magmatism in the Langtang Valley, Nepal Himalaya. J Petrol 34:345–368

    Article  Google Scholar 

  • Jamieson RA, Unsworth MJ, Harris NBW et al (2011) Crustal melting and the flow of mountains. Elements 7:253–260

    Article  Google Scholar 

  • King J, Harris N, Argles T et al (2010) Contribution of crustal anatexis to the tectonic evolution of Indian crust beneath southern Tibet. Geol Soc Am Bull 123:218–239. doi:10.1130/B30085.1

    Article  Google Scholar 

  • Kohn MJ (2008) 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 120:259–273. doi:10.1130/B26252.1

    Article  Google Scholar 

  • Kohn MJ, Wieland MS, Parkinson CD, Upreti BN (2005) Five generations of monazite in Langtang gneisses: implications for chronology of the Himalayan metamorphic core. J Metamorph Geol 23:399–406. doi:10.1111/j.1525-1314.2005.00584.x

    Article  Google Scholar 

  • Kylander-Clark ARC, Hacker BR, Cottle JM (2013) Laser-ablation split-stream ICP petrochronology. Chem Geol 345:99–112. doi:10.1016/j.chemgeo.2013.02.019

    Article  Google Scholar 

  • Langille JM, Jessup MJ, Cottle JM et al (2012) Timing of metamorphism, melting and exhumation of the Leo Pargil dome, northwest India. J Metamorph Geol. doi:10.1111/j.1525-1314.2012.00998.x

    Google Scholar 

  • Larson KP, Godin L, Price RA (2010) Relationships between displacement and distortion in orogens: linking the Himalayan foreland and hinterland in central Nepal. Geol Soc Am Bull 122:1116–1134. doi:10.1130/B30073.1

    Article  Google Scholar 

  • Lee J, Hacker B, Dinklage W, Wang Y (2000) Evolution of the Kangmar Dome, southern Tibet: structural, petrologic, and thermochronologic constraints. Tectonics 19:872–895

    Article  Google Scholar 

  • Lee J, Hacker B, Wang Y (2004) Evolution of North Himalayan gneiss domes: structural and metamorphic studies in Mabja Dome, southern Tibet. J Struct Geol 26:2297–2316. doi:10.1016/j.jsg.2004.02.013

    Article  Google Scholar 

  • Leech ML (2008) Does the Karakoram fault interrupt mid-crustal channel flow in the western Himalaya? Earth Planet Sci Lett 276:314–322. doi:10.1016/j.epsl.2008.10.006

    Article  Google Scholar 

  • Leech ML (2009) Reply to comment by M. P. Searle and R. J. Phillips (2009) and R. R. Parrish (2009) on: “Does the Karakoram fault interrupt mid-crustal channel flow in the western Himalaya?” by Mary L. Leech, Earth and Planetary Science Letters 276 (2008) 314–322. Earth Planet Sci Lett 286:592–595. doi:10.1016/j.epsl.2009.05.039

  • Ludwig KR (2000) User’s manual for Isoplot/Ex version 2.4: a geochronological toolkit for Microsoft Excel. Berkeley Geochronological Center, Special Publication No. 1a

  • Makovsky Y, Klemperer S, Ratschbacher L et al (1996) INDEPTH wide-angle reflection observation of P-wave-to-S-wave conversion from crustal bright spots in Tibet. Science 274:1690–1691

    Article  Google Scholar 

  • Marquer D, Chawla HS, Challandes N (2000) Pre-alpine high grade metamorphism in High Himalaya. Eclogae Geol Helv 93:207–220

    Google Scholar 

  • McDonough W, Sun S (1995) The composition of the Earth. Chem Geol 2541:223–253

    Article  Google Scholar 

  • Miller C, Thöni M, Frank W et al (2001) The early Palaeozoic magmatic event in the northwest Himalaya, India: source, tectonic setting and age of emplacement. Geol Mag 138:237–251. doi:10.1017/S0016756801005283

    Article  Google Scholar 

  • Montel J (1986) Experimental determination of the solubility of Ce-monazite in SiO2–Al2O3–K2O–Na2O melts at 800°C, 2 kbar, under H2O-saturated conditions. Geology 14:659–662. doi:10.1130/0091-7613(1986)14<659

    Article  Google Scholar 

  • Montel J-M (1993) A model for monazite/melt equilibrium and application to the generation of granitic magmas. Chem Geol 110:127–146. doi:10.1016/0009-2541(93)90250-M

    Article  Google Scholar 

  • Murphy MA, Yin A, Kapp P et al (2002) Structural evolution of the Gurla Mandhata detachment system, southwest Tibet: implications for the eastward extent of the Karakoram fault system. Geol Soc Am Bull 114:428–447. doi:10.1130/0016-7606(2002)114<0428:SEOTGM>2.0.CO;2

    Article  Google Scholar 

  • Nabelek PI, Liu M (2007) Petrologic and thermal constraints on the origin of leucogranites in collisional orogens. Trans R Soc Edinb Earth Sci 95:73–85. doi:10.1017/S0263593300000936

    Google Scholar 

  • Nabelek PI, Whittington AG, Hofmeister AM (2010) Strain heating as a mechanism for partial melting and ultrahigh temperature metamorphism in convergent orogens: implications of temperature-dependent thermal diffusivity and rheology. J Geophys Res 115:1–17. doi:10.1029/2010JB007727

    Article  Google Scholar 

  • Nelson KD, Zhao W, Brown LD, Kuo J, Che J, Liu X, Klemperer SL et al (1996) Partially molten middle crust beneath southern Tibet: synthesis of project INDEPTH results. Science 274(5293):1684–1688

    Article  Google Scholar 

  • Parrish R (1990) U-Pb dating of monazite and its application to geological problems. Can J Earth Sci 27:1431–1450

    Article  Google Scholar 

  • Parrish RR (2009) Comment on: “Does the Karakoram fault interrupt mid-crustal channel flow in the western Himalaya?” by Mary L. Leech, Earth and Planetary Science Letters 276 (2008) 314–322. Earth Planet Sci Lett 286:586–588. doi:10.1016/j.epsl.2009.05.038

  • Parrish R, Hodges K (1996) Isotopic constraints on the age and provenance of the Lesser and Greater Himalayan sequences, Nepalese Himalaya. Geol Soc Am Bull 108:904–911. doi:10.1130/0016-7606(1996)108<0904

    Article  Google Scholar 

  • Paterson M (2001) A granular flow theory for the deformation of partially molten rock. Tectonophysics 335:51–61

    Article  Google Scholar 

  • Paton C, Woodhead JD, Hellstrom JC et al (2010) Improved laser ablation U–Pb zircon geochronology through robust downhole fractionation correction. Geochem Geophys Geosyst. doi:10.1029/2009GC002618

    Google Scholar 

  • Pognante U, Castelli D, Benna P et al (1990) The crystalline units of the High Himalayas in the Lahul–Zanskar region (northwest India): metamorphic–tectonic history and geochronology of the collided and imbricated Indian plate. Geol Mag 127:101–116. doi:10.1017/S0016756800013807

    Article  Google Scholar 

  • Prince C, Harris N, Vance D (2001) Fluid-enhanced melting during prograde metamorphism. J Geol Soc 158:233–241. doi:10.1144/jgs.158.2.233

    Article  Google Scholar 

  • Pyle J, Spear F (2003) Four generations of accessory-phase growth in low-pressure migmatites from SW New Hampshire. Am Miner 88:338–351

    Google Scholar 

  • Quigley MC, Liangjun Y, Gregory C et al (2008) U-Pb SHRIMP zircon geochronology and T–t–d history of the Kampa Dome, southern Tibet. Tectonophysics 446:97–113. doi:10.1016/j.tecto.2007.11.004

    Article  Google Scholar 

  • Rapp RP, Watson EB (1986) Monazite solubility and dissolution kinetics: implications for the thorium and light rare earth chemistry of felsic magmas. Contrib Miner Petrol 94:304–316. doi:10.1007/BF00371439

    Article  Google Scholar 

  • Reichardt H, Weinberg RF, Andersson UB, Fanning CM (2010) Hybridization of granitic magmas in the source: the origin of the Karakoram Batholith, Ladakh, NW India. Lithos 116:249–272. doi:10.1016/j.lithos.2009.11.013

    Article  Google Scholar 

  • Robinson DM, DeCelles PG, Copeland P (2006) Tectonic evolution of the Himalayan thrust belt in western Nepal: implications for channel flow models. Geol Soc Am Bull 118:865–885. doi:10.1130/B25911.1

    Article  Google Scholar 

  • Rosenberg CL, Handy MR (2005) Experimental deformation of partially melted granite revisited: implications for the continental crust. J Metamorph Geol 23:19–28. doi:10.1111/j.1525-1314.2005.00555.x

    Article  Google Scholar 

  • Royden L (1993) The steady-state thermal structure of eroding orogenic belts and accretionary prisms. J Geophys Res 98:4487–4507

    Article  Google Scholar 

  • Rubin A (1995) Getting granite dikes out of the source region. J Geophys Res 100:5911–5929

    Article  Google Scholar 

  • Sawyer E (1994) Melt segregation in the continental crust. Geology 22:1019–1022. doi:10.1130/0091-7613(1994)022<1019

    Article  Google Scholar 

  • Sawyer EW (2001) Melt segregation in the continental crust: distribution and movement of melt in anatectic rocks. J Metamorph Geol 19:291–309. doi:10.1046/j.0263-4929.2000.00312.x

    Article  Google Scholar 

  • Scaillet B, France-Lanord C, Le Fort P (1990) Badrinath-Gangotri plutons (Garhwal, India) petrological and geochemical evidence for fractionation processes in a high Himalayan leucogranite. J Volcanol Geoth Res 44:163–188

    Article  Google Scholar 

  • Scaillet B, Holtz F, Pichavant M, Schmidt M (1996) Viscosity of Himalayan leucogranites: implications for mechanisms of granitic magma ascent. J Geophys Res 101:27691–27699

    Article  Google Scholar 

  • Schärer U (1984) The effect of initial 230Th disequilibrium on young U-Pb ages: the Makalu case, Himalaya. Earth Planet Sci Lett 67:191–204

    Article  Google Scholar 

  • Schärer U, Allègre CJ (1983) The Palung granite (Himalaya); high-resolution U–Pb systematics in zircon and monazite. Earth Planet Sci Lett 63:423–432

    Article  Google Scholar 

  • Schärer U, Xu R, Allègre C (1986) U-(Th)-Pb systematics and ages of Himalayan leucogranites, South Tibet. Earth Planet Sci Lett 77:35–48

    Article  Google Scholar 

  • Schulmann K, Lexa O, Štípská P et al (2008) Vertical extrusion and horizontal channel flow of orogenic lower crust: key exhumation mechanisms in large hot orogens? J Metamorph Geol 26:273–297. doi:10.1111/j.1525-1314.2007.00755.x

    Article  Google Scholar 

  • Searle MP, Phillips RJ (2009) Comment on: “Does the Karakoram fault interrupt mid-crustal channel flow in the western Himalaya?” by Mary L. Leech, Earth and Planetary Science Letters 276 (2008) 314–322. Earth Planet Sci Lett 286:589–591. doi:10.1016/j.epsl.2009.05.036

  • Searle M, Noble S, Hurford A, Rex D (1999) Age of crustal melting, emplacement and exhumation history of the Shivling Leucogranite, Garhwal Himalaya. Geol Mag 136:513–525

    Article  Google Scholar 

  • Searle MP, Cottle JM, Streule MJ, Waters DJ (2010) Crustal melt granites and migmatites along the Himalaya: melt source, segregation, transport and granite emplacement mechanisms. Earth Environ Sci Trans R Soc Edinb 100:219–233. doi:10.1017/S175569100901617X

    Article  Google Scholar 

  • Seydoux-Guillaume A-M, Paquette J-L, Wiedenbeck M et al (2002) Experimental resetting of the U–Th–Pb systems in monazite. Chem Geol 191:165–181. doi:10.1016/S0009-2541(02)00155-9

    Article  Google Scholar 

  • Simpson R, Parrish R, Searle M, Waters D (2000) Two episodes of monazite crystallization during metamorphism and crustal melting in the Everest region of the Nepalese Himalaya. Geology 28:403–406. doi:10.1130/0091-7613(2000)28<403

    Article  Google Scholar 

  • Steiger R, Jäger E (1977) Subcommission on geochronology: convention on the use of decay constants in geo-and cosmochronology. Earth Planet Sci Lett 36:359–362

    Article  Google Scholar 

  • Stepanov AS, Hermann J, Rubatto D, Rapp RP (2012) Experimental study of monazite/melt partitioning with implications for the REE, Th and U geochemistry of crustal rocks. Chem Geol 300–301:200–220. doi:10.1016/j.chemgeo.2012.01.007

    Article  Google Scholar 

  • Teyssier C, Whitney D (2002) Gneiss domes and orogeny. Geology 30:1139–1142. doi:10.1130/0091-7613(2002)030<1139

    Article  Google Scholar 

  • Thiede RC, Arrowsmith JR, Bookhagen B et al (2006) Dome formation and extension in the Tethyan Himalaya, Leo Pargil, northwest India. Geol Soc Am Bull 118:635–650. doi:10.1130/B25872.1

    Article  Google Scholar 

  • Thompson A, Connolly J (1995) Melting of the continental crust: some thermal and petrological constraints on anatexis in continental collision zones and other tectonic settings. J Geophys Res 100:15565–15579

    Article  Google Scholar 

  • Thöni M, Miller C, Hager C et al (2012) New geochronological constraints on the thermal and exhumation history of the Lesser and Higher Himalayan Crystalline Units in the Kullu–Kinnaur area of Himachal Pradesh (India). J Asian Earth Sci 52:98–116. doi:10.1016/j.jseaes.2012.02.015

    Article  Google Scholar 

  • Unsworth MJ, Jones AG, Wei W et al (2005) Crustal rheology of the Himalaya and Southern Tibet inferred from magnetotelluric data. Nature 438:78–81. doi:10.1038/nature04154

    Article  Google Scholar 

  • Vermeesch P (2012) On the visualisation of detrital age distributions. Chem Geol 312–313:190–194. doi:10.1016/j.chemgeo.2012.04.021

    Article  Google Scholar 

  • Viskupic K, Hodges KV (2001) Monazite–xenotime thermochronometry: methodology and an example from the Nepalese Himalaya. Contrib Miner Petrol 141:233–247. doi:10.1007/s004100100239

    Article  Google Scholar 

  • Viskupic K, Hodges KV, Bowring SA (2005) Timescales of melt generation and the thermal evolution of the Himalayan metamorphic core, Everest region, eastern Nepal. Contrib Miner Petrol 149:1–21. doi:10.1007/s00410-004-0628-5

    Article  Google Scholar 

  • Watt G, Harley S (1993) Accessory phase controls on the geochemistry of crustal melts and restites produced during water-undersaturated partial melting. Contrib Miner Petrol 114:550–566

    Article  Google Scholar 

  • Weinberg R (1996) Ascent mechanism of felsic magmas: news and views. Trans R Soc Edinb Earth Sci 87:95–103. doi:10.1017/S0263593300006519

    Article  Google Scholar 

  • Weinberg RF (1999) Mesoscale pervasive felsic magma migration: alternatives to dyking. Lithos 46:393–410. doi:10.1016/S0024-4937(98)00075-9

    Article  Google Scholar 

  • Weinberg RF, Mark G (2008) Magma migration, folding, and disaggregation of migmatites in the Karakoram Shear Zone, Ladakh, NW India. Geol Soc Am Bull 120:994–1009. doi:10.1130/B26227.1

    Article  Google Scholar 

  • White N, Parrish R, Bickle M et al (2001) Metamorphism and exhumation of the NW Himalaya constrained by U–Th–Pb analyses of detrital monazite grains from early foreland basin sediments. J Geol Soc 158:625–635

    Article  Google Scholar 

  • Whitney D, Evans B (2010) Abbreviations for names of rock-forming minerals. Am Miner 95:185–187. doi:10.2138/am.2010.3371

    Article  Google Scholar 

  • Williams M, Jercinovic M, Terry M (1999) Age mapping and dating of monazite on the electron microprobe: deconvoluting multistage tectonic histories. Geology 27:1023–1026. doi:10.1130/0091-7613(1999)027<1023

    Article  Google Scholar 

  • Williams ML, Jercinovic MJ, Hetherington CJ (2007) Microprobe monazite geochronology: understanding geologic processes by integrating composition and chronology. Annu Rev Earth Planet Sci 35:137–175. doi:10.1146/annurev.earth.35.031306.140228

    Article  Google Scholar 

  • Williams ML, Jercinovic MJ, Harlov DE et al (2011) Resetting monazite ages during fluid-related alteration. Chem Geol 283:218–225. doi:10.1016/j.chemgeo.2011.01.019

    Article  Google Scholar 

  • Wolf M, London D (1995) Incongruent dissolution of REE-and Sr-rich apatite in peraluminous granitic liquids: differential apatite, monazite, and xenotime solubilities during anatexis. Am Miner 80:765–775

    Google Scholar 

  • Zeitler P, Koons P, Bishop M et al (2001) Crustal reworking at Nanga Parbat, Pakistan: metamorphic consequences of thermal-mechanical coupling facilitated by erosion. Tectonics 20:712–728. doi:200110.1029/2000TC001243

    Article  Google Scholar 

  • Zeng L, Asimow PD, Saleeby JB (2005) Coupling of anatectic reactions and dissolution of accessory phases and the Sr and Nd isotope systematics of anatectic melts from a metasedimentary source. Geochim Cosmochim Acta 69:3671–3682. doi:10.1016/j.gca.2005.02.035

    Article  Google Scholar 

  • Zhang H, Harris N, Parrish R et al (2004) Causes and consequences of protracted melting of the mid-crust exposed in the North Himalayan antiform. Earth Planet Sci Lett 228:195–212. doi:10.1016/j.epsl.2004.09.031

    Article  Google Scholar 

  • Zhu XK, O’Nions RK (1999) Monazite chemical composition: some implications for monazite geochronology. Contrib Miner Petrol 137:351–363. doi:10.1007/s004100050555

    Article  Google Scholar 

Download references

Acknowledgments

Funding for this project was provided by National Science Foundation grants (EAR-0911416 and EAR-1119380) awarded to J. Cottle and (EAR-0911561) to M. Jessup. We thank A. Kylander-Clark and G. Seward for assistance with LA-ICPMS and EPMA data collection. P. E. Lee provided valuable assistance in the field. We wish to thank two anonymous reviewers for their thoughtful reviews of an earlier version of this manuscript as well as Franck Poitrasson for his helpful editorial assistance.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Graham W. Lederer.

Additional information

Communicated by F. Poitrasson.

Electronic supplementary material

Appendix 1: Analytical methods

Appendix 1: Analytical methods

EPMA X-ray chemical mapping

Analyses were carried out in beam scan mode using 15 kV accelerating voltage, 200 nA beam current (equating to a ~1 μm3 interaction volume), and a dwell time of 25 ms. Monazite is relatively homogeneous with respect to the LREE, but may show considerable variation in Th, U, and Y, with the geochemical behavior of Y serving as a proxy for HREE (Foster et al. 2004). Understanding the distribution of these elements potentially provides important information on the growth history of individual crystals (Cocherie et al. 1998; Stepanov et al. 2012; Williams et al. 1999, 2007; Zhu and O’Nions 1999).

LA-MC-ICPMS U–Th/Pb geochronology

The laser system utilizes a HelEx (“helium excimer”) sample cell (Eggins et al. 1998, 2005) designed for enhanced signal intensity and rapid washout times using He carrier gas. Helium carrier gas conveys the laser aerosol to a glass mixing-bulb where Ar is added to stabilize the input to the plasma. Boiled liquid argon and ultra-high purity helium are passed through activated charcoal and gold-coated quartz sand filters upstream of the mass flow controllers to reduce 204X (where X includes 204Pb and 204Hg) backgrounds to <200 cps. The collector array on the Nu Plasma is configured to measure 238U and 232Th on two high-mass side Faraday cups equipped with 1011 ohm resistors and 208Pb, 207Pb, 206Pb, and 204X on four low-mass side ETP discrete dynode secondary electron multipliers.

Ablations were conducted for 40 s each at 4.8 J/cm2 fluence, a frequency of 3 Hz, and a pit diameter of approximately 7 μm yielding craters 5–6 μm deep (as assessed by optical microscopy). Five to ten spot analyses were collected on each monazite grain, targeting domains with different trace element chemistry visible in X-ray maps, including cores and rims. Location of individual laser pits was confirmed with an optical microscope after analysis. Utilizing a standard-sample bracketing technique, analyses of reference materials with known isotopic compositions were measured before and after each set of ten unknown analyses. Reference materials consisted of several monazite grains or fragments with matrices similar to the unknowns and published isotopic ages including “44069” (424 Ma Pb/U ID-TIMS age; Aleinikoff et al. 2006), “FC-1” (55.7 Ma Pb/U ID-TIMS age; Horstwood et al. 2003), and “554” (45 Ma Pb/Th age; Harrison et al. 1999). Concordia and weighted mean date plots were calculated in Isoplot v2.4 (Ludwig 2000) using the 238U, 235U, and 232Th decay constants of Steiger and Jäger (1977).

LA-ICPMS Trace Element analysis

Chemical domains identified during X-ray mapping were targeted for trace element analysis by sampling next to U–Th/Pb ablation pits. Following analysis, optical petrographic microscope images of monazite grains were compared to X-ray maps to ensure trace element and U–Th/Pb ablation pitfall within targeted chemical domains. Additionally, the ablation profile was inspected for anomalous or abrupt changes in intensity, and based on this three-dimensional assessment of whether each spot analysis sampled a single domain, analyses located on domain boundaries or fractures were excluded from the data set. Ablations were conducted for 30 s each at 3.2 J/cm2 fluence, a frequency of 3 Hz, and a pit diameter of approximately 6 μm yielding craters 3–4 μm deep.

Because the AttoM is a relatively new instrument, we briefly describe the analytical routine below. In Linked Scan mode, the magnet current is ramped up and down in a controlled manner such that a complete cycle (m/z 6–250–6) can be completed every 220 ms (100 ms each direction + 20 ms settle time). To maximize counting time, each isotope of interest is deflected into the single discrete dynode secondary electron multiplier by simultaneous use of the magnet and the post-ESA deflectors. As the magnet sweeps, each mass remains in the ion counter for up to 40 % of its mass along the magnet sweep. Elemental abundances and their uncertainties are calculated using a simple matrix-matched sample-standard bracketing approach in Iolite v. 2.1.2 (Paton et al. 2010), including corrections for baseline and instrumental drift.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Lederer, G.W., Cottle, J.M., Jessup, M.J. et al. Timescales of partial melting in the Himalayan middle crust: insight from the Leo Pargil dome, northwest India. Contrib Mineral Petrol 166, 1415–1441 (2013). https://doi.org/10.1007/s00410-013-0935-9

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00410-013-0935-9

Keywords

Navigation