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Element redistribution and mobility during upper crustal metamorphism of metasedimentary rocks: an example from the eastern Mount Lofty Ranges, South Australia

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Abstract

We present a detailed study on element mobility during prograde metamorphism of metasedimentary rocks of the eastern Mt. Lofty Ranges, South Australia. Mineral and bulk rock compositions were monitored across a regional metamorphic gradient from ≈350–400 °C to migmatite grade (≈650–700 °C) at ≈0.3–0.5 GPa, where pervasive up-temperature fluid flow during metamorphism has been proposed previously. Major and most trace elements (including rare earth elements) are isochemical during metamorphism as they are effectively redistributed into newly formed major and/or accessory minerals. Monazite or allanite and xenotime control the whole rock concentration of rare earth elements (REEs), whereas apatite and titanite are minor REE hosts. The only non-volatile elements that are demonstrably mobilized by metamorphic fluids are Zn, Pb, Ag, Cs, Sb, Bi and As, whose concentrations decreased with increasing metamorphic grade. Depletion of Zn, Sb and Pb was progressive with increasing temperature in staurolite-absent psammopelites, with losses of ≈80 % of the original Zn and >80 % of the protolithic Sb and ≈50 % of the original Pb from the rocks from high-grade metamorphic zones. Pronounced depletion of As and Cs occurs at the greenschist/amphibolite facies boundary and the transition to migmatite grade, respectively, while Ag and Bi contents decrease between 500 and 550 °C where >50 % of the original Ag and Bi is lost. While for most elements, unmetamorphosed sedimentary sequences can be considered chemical equivalents of metasedimentary rocks occupying deeper crust levels, in some cases, such as the extensive flow of Cl-rich fluid documented here, metals such as Zn, Pb and Ag may be stripped and may serve as a metal source for orebody formation. The decrease of As, Bi and Sb contents during prograde metamorphism might be a more universal feature that is linked with sulphide phase transitions.

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References

  • Afshooni SZ, Mirnejad H, Esmaeily D, Haroni HA (2013) Mineral chemistry of hydrothermal biotite from the Kahang porphyry copper deposit (NE Isfahan), Central Province of Iran. Ore Geol Rev 54:214–232

    Article  Google Scholar 

  • Ague JJ (1994) Mass transfer during Barrovian metamorphism of pelites, South-Central Connecticut, I: evidence for changes in composition and volume. Am J Sci 294:989–1057

    Article  Google Scholar 

  • Arnold J, Sandiford M (1990) Petrogenesis of cordierite-orthoamphibole assemblages from the Springton region, South Australia. Contrib Mineral Petrol 106:100–109

    Article  Google Scholar 

  • Bea F (1996) Residence of REE, Y, Th and U in granites and crustal protoliths. Implications for the chemistry of crustal melts. J Petrol 37:521–552

    Article  Google Scholar 

  • Bea F, Montero P (1999) Behavior of accessory phases and redistribution of Zr, REE, Y, Th, and U during metamorphism and partial melting of metapelites in the lower crust: an example from the Kinzigite Formation of Ivrea-Verbano, NW Italy. Geochim Cosmochim Acta 63:1133–1153

    Article  Google Scholar 

  • Bea F, Pereira MD, Stroh A (1994) Mineral/leucosome trace-element partitioning in a peraluminous migmatite (a laser ablation-ICP-MS study). Chem Geol 117:291–312

    Article  Google Scholar 

  • Bebout GE, Ryan JG, Leeman WP, Bebout AE (1999) Fractionation of trace elements by subduction-zone metamorphism effect of convergent-margin thermal evolution. Earth Plan Sci Let 171:63–81

    Article  Google Scholar 

  • Bebout GE, Bebout AE, Graham CM (2007) Cycling of B, Li, and LILE (K, Cs, Rb, Ba, Sr) into subduction zones: SIMS evidence from micas in high-P/T metasedimentary rocks. Chem Geol 239:284–304

    Article  Google Scholar 

  • Benning LG, Seward TM (1996) Hydrosulphide complexing of Au(I) in hydrothermal solutions from 150–400 °C and 500–1500 bar. Geochim Cosmochim Acta 60:1849–1871

    Article  Google Scholar 

  • Berger A, Rosenberg C, Schaltegger U (2009) Stability and isotopic dating of monazite and allanite in partially molten rocks: examples from the Central Alps. Swiss J Geosci 102:15–29

    Article  Google Scholar 

  • Bingen B, Demaiffe D, Hertogen J (1996) Redistribution of rare earth elements, thorium, and uranium over accessory minerals in the course of amphibolite to granulite facies metamorphism: the role of apatite and monazite in orthogneisses from southwestern Norway. Geochim Cosmochim Acta 60:1341–1354

    Article  Google Scholar 

  • Cardenas AA, Girty GH, Hanson AD, Lahren MM, Knaack C, Johnson D (1996) Assessing differences in composition between low metamorphic grade mudstones and high-grade schists using logratio techniques. J Geol 104:279–293

    Article  Google Scholar 

  • Cartwright I, Vry J, Sandiford M (1995) Changes in stable isotope ratios of metapelite and marbles during regional metamorphism, Mount Lofty Ranges, South Australia: implications for crustal scale fluid flow. Contrib Mineral Petrol 120:292–310

    Article  Google Scholar 

  • Cherniak DJ (1995) Diffusion of lead in plagioclase and K-feld-spar: an investigation using Rutherford backscattering and resonant nuclear reaction analysis. Contrib Mineral Petrol 120:358–371

    Article  Google Scholar 

  • Cook NDJ, Ashley PM (1992) Meta-evaporite sequence, exhalative chemical sediments and associated rocks in the Proterozoic Willyama Supergroup, South Australia: implications for metallogenesis. Precambrian Res 56:211–226

    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

    Article  Google Scholar 

  • Coulson IM, Dipple GM, Raudsepp M (2001) Evolution of HF and HCl activity in magmatic volatiles of the gold-mineralized Emerald Lake pluton, Yukon Territory, Canada. Miner Depos 36:594–606

    Article  Google Scholar 

  • Cullers RL (2002) Implications of elemental concentrations for provenance, redox conditions, and metamorphic studies of shales and limestones near Pueblo, CO, USA. Chem Geol 191:305–327

    Article  Google Scholar 

  • Dymoke P, Sandiford M (1992) Phase relationships in Buchan facies series pelitic assemblages: calculations with application to andalusite–staurolite parageneses in the Mount Lofty Ranges, South Australia. Contrib Mineral Petrol 100:121–132

    Article  Google Scholar 

  • Evans J, Zalasiewicz J (1996) U-Pb, Pb–Pb and Sm–Nd dating of authigenic monazite: implications for the diagenetic evolution of the Welsh Basin. Earth Plan Sci Let 144:421–433

    Article  Google Scholar 

  • Ferry JM (1983) Mineral reactions and element migration during metamorphism of calcereous sediments from the Vassalboro Formation, south-central Maine. Am Mineral 68:334–354

    Google Scholar 

  • Fitzsimons ICW, Kinny PD, Wetherley S, Hollingsworth DA (2005) Bulk chemical control on metamorphic monazite growth in pelitic schists and implications for U–Pb age data. J Metamorph Geol 23:261–277

    Article  Google Scholar 

  • Foden J, Sandiford M, Dougherty-Page J, Williams I (1999) Geochemistry and geochronology of the Rathjen Gneiss: implications for the early tectonic evolution of the Delamarian Orogeny. Aust J Earth Sci 46:377–389

    Article  Google Scholar 

  • Foden J, Barovich K, Jane M, O'Halloran G (2001) Sr-isotopic evidene for late Neoproterozoic rifting in the Adelaide Geosyncline at 586 Ma: implications for a Cu ore forming fluid flux. Precambrian Res 106:291–308

    Article  Google Scholar 

  • Foden JD, Elburg MA, Turner SP, Sandiford M, O’Callaghan J, Mitchell S (2002) Granite production in the Delamarian Orogen, South Australian. J Geol Soc Lond 159:557–575

    Article  Google Scholar 

  • Frost BR, Chamberlain KR, Schumacher JC (2001) Sphene (titanite): phase relations and role as a geochronometer. Chem Geol 172:131–148

    Article  Google Scholar 

  • Garofalo PS (2012) The composition of Alpine marine sediments (Bünderschiefer Formation, W Alps) and the mobility of their chemical components during orogenic Metamorphism. Lithos 128:55–72

    Article  Google Scholar 

  • Gibson GM, Ireland TR (1996) Extension of the Delamerian (Ross) orogen into western New Zealand: evidence from zircon ages and implications for crustal growth along the Pacific margin of Gondwana. Geology 24:1087–1090

    Article  Google Scholar 

  • Giére R, Oberli F, Meier M (1988) Mobility of Ti, Zr and REE—mineralogical, geochemical and isotopic evidence from the Adamello contact aureole (Italy). Chem Geol 70:161

    Article  Google Scholar 

  • Haack U, Heinrichs H, Boness M, Schneider A (1984) Loss of metals from pelites during regional metamorphism. Contrib Mineral Petrol 85:116–132

    Article  Google Scholar 

  • Hammerli J, Rusk B, Spandler C, Emsbo P, Oliver NHS (2013) In situ quantification of Br and Cl in minerals and fluid inclusions by LA-ICP-MS: a powerful tool to identify fluid sources. Chem Geol 337–338:75–87

    Article  Google Scholar 

  • Hammerli J, Rubenach M (2016) The role of halogens during contact and regional metamorphism. In: Harlov D, Aranovich L (eds) The role of halogens in terrestrial and extraterrestrial geochemical processes: surface, crust, and mantle. Springer, Berlin

  • Hammerli J, Kemp AI, Spandler C (2014a) Neodymium isotope equilibration during crustal metamorphism revealed by in situ microanalysis of REE-rich accessory minerals. Earth Plan Sci Lett 392:133–142

    Article  Google Scholar 

  • Hammerli J, Spandler C, Oliver NHS, Rusk B (2014b) Cl/Br of scapolite as a fluid tracer in the earth’s crust: insights into fluid sources in the Mary Kathleen Fold Belt, Mt. Isa Inlier, Australia. J Metamorph Geol 32:93–112

    Article  Google Scholar 

  • Hammerli J, Spandler C, Oliver NHS, Sossi P, Dipple GM (2015) Zn and Pb mobility during metamorphism of sedimentary rocks and potential implications for some base metal deposits. Miner Depos 50:657–664

    Article  Google Scholar 

  • Heier KS, Brunfelt AO (1970) Concentration of Cs in high grade metamorphic rocks. Earth Plan Sci Let 9:416–420

    Article  Google Scholar 

  • Heinrichs H, Schulz-Dobrick B, Wedepohl KH (1980) Terrestrial geochemistry of Cd, Bi, T1, Zn and Rb. Geochim Cosmochim Acta 44:1519–1533

    Article  Google Scholar 

  • Henderson AL, Foster GJ, Najman Y (2010) Testing the application of in situ Sm–Nd isotopic analysis on detrital apatites: a provenance tool for constraining the timing of India–Eurasia collision. Earth Plan Sci Lett 297:42–49

    Article  Google Scholar 

  • Holm RJ, Spandler C, Richards SW (2013) Melanesian arc far-field response to collision of the Ontong Java Plateau: geochronology and petrogenesis of the Simuku Igneous Complex, New Britain, Papua New Guinea. Tectonophysics 603:189–212

    Article  Google Scholar 

  • Ilton ES, Eugster HP (1989) Base metal exchange between magnetite and a chloride-rich hydrothermal fluid. Geochim Cosmochim Acta 53:291–301

    Article  Google Scholar 

  • Ilton ES, Eugster HP (1990) Partitioning o f base metals between silicates, oxides, and a chloride-rich hydrothermal fluid. I. Evaluation of data derived from experimental and natural assemblages. In: Spencer RJ, Ming Chou I (eds) Fluid–mineral interactions: a Tribute to H.P. Eugster. Geochem. Soc, Spec. Publ. 2, pp 157–169

  • Jago JB, Gum JC, Burtt AC, Haines PW (2003) Stratigraphy of the Kanmantoo Group: a critical element of the Adelaide Fold Belt and the Palaeo-Pacific plate margin, Eastern Gondwana. Aust J Earth Sci 50:343–363

    Article  Google Scholar 

  • Janots E, Engi M, Berger A, Allaz J, Schwarz J-O, Spandler C (2008) Prograde metamorphic sequence of REE minerals in pelitic rocks of the Central Alps: implications for allanite–monazite–xenotime phase relation from 250 to 610 & #xB0;C. J Metamorph Geol 26:509–526

    Article  Google Scholar 

  • Kent AJR, Ashley PM, Fanning CM (2000) Metasomatic alteration associated with regional metamorphism: an example from the Willyama Supergroup, South Australia. Lithos 54:33–62

    Article  Google Scholar 

  • Korh EA, Schmidt STH, Ulianov A, Potel S (2009) Trace element partitioning in HP-LT metamorphic assemblages during subduction related assemblages during subduction-related metamorphism, Ile de Groix, France: a detailed LA-ICPMS study. J Petrol 50:1107–1148

    Article  Google Scholar 

  • Korzhinskii DS (1965) The theory of systems with perfectly mobile components and processes of mineral formation. Am J Sci 263:193–205

    Article  Google Scholar 

  • Kwak TAP (1977) Scapolite compositional change in a metamorphic gradient and its bearing on the identification of meta-evaporite sequences. Geol Mag 114:343–354

    Article  Google Scholar 

  • Leach DL, Sangster DF, Kelley KD, Large RR, Garven G, Allen CR, Gutzmer J, Walters S (2005) Sediment-hosted lead–zinc deposits: a global perspective. Econ Geol 100:561–607

    Google Scholar 

  • Lebedev VI, Nagaytsev YuV (1980) Minor elements in metamorphic rocks as an ore-metal source for certain deposits. Geochem Intern 17:31

  • Masters RL, Ague JJ (2005) Regional-scale fluid flow and element mobility in Barrow’s metamorphic zones, Stonehaven, Scotland. Contrib Mineral Petrol 150:1–18

    Article  Google Scholar 

  • Mora CI, Valley JW (1989) Halogen-rich scapolite and biotite: implications for metamorphic fluid-rock interaction. Am Mineral 74:721–737

    Google Scholar 

  • Moss BE, Haskin LA, Dymek RF, Shaw DM (1995) Redetermination and reevaluation of compositional variations in metamorphosed sediments of the Littelton Formation, New Hampshire. Am J Sci 295:988–1019

    Article  Google Scholar 

  • Moss BE, Haskin LA, Dymek RF (1996) Compositional variations in metamorphosed sediments of the Littleton Formation, New Hampshire, and the Carrabassett Formation, Maine, at sub-hand specimen outcrop, and regional scales. Am J Sci 296:473–505

    Article  Google Scholar 

  • Munoz JL (1984) F–OH and Cl–OH exchange in micas with applications to hydrothermal ore deposits. In Bailey SW (ed) Micas. Reviews in Mineralogy, Mineral Soc Am 13:469–494

  • Offler R, Fleming PD (1968) A synthesis of folding and metamorphism in the Mt Lofty Ranges, South Australia. J Geol Soc Aust 15:245–266

    Article  Google Scholar 

  • Oliver NHS (1995) Hydrothermal history of the Mary Kathleen Fold Belt, Mt Isa Block, Queensland. Aust J Earth Sci 42:267–279

    Article  Google Scholar 

  • Oliver NHS, Wall VJ, Cartwright I (1992) Internal control of fluid compositions in amphibolite-facies scapolitic calc-silicates, Mary Kathleen, Australia. Contrib Mineral Petrol 111:94–112

    Article  Google Scholar 

  • Oliver NHS, Dipple GM, Cartwright I, Schiller J (1998) Fluid flow and metasomatism in the genesis of the amphibolite-facies, pelite-hosted Kanmantoo copper deposit, South Australia. Am J Sci 298:181–218

    Article  Google Scholar 

  • Oliver NHS, Butera KM, Rubenach MJ, Marshall LJ, Cleverley JS, Mark G, Tullemans F, Esser D (2008) The protracted hydrothermal evolution of the Mount Isa Eastern Succession: a review and tectonic implications. Precambrian Res 163:108–130

    Article  Google Scholar 

  • Pitcairn IK, Teagle DAH, Craw D, Olivo GR, Kerrich R, Brewer TS (2006) Sources of metals and fluids in orogenic gold deposits. Insights from the Otago and Alpine Schists, New Zealand. Econ Geol 101:1525–1546

    Article  Google Scholar 

  • Pitcairn IK, Olivio GR, Teagle DAH, Craw D (2010) Sulfide evolution during prograde metamorphism of the Otago and Alpine Schists, New Zealand. Can Mineral 48:1267–1295

    Article  Google Scholar 

  • Pitcairn IK, Skelton ADL, Wohlgemuth-Ueberwasser CC (2015) Mobility of gold during metamorphism of the Dalradian in Scotland. Lithos 233:69–88

    Article  Google Scholar 

  • Plank T, Langmuir CH (1998) The geochemical composition of subducting sediment and its consequences for the crust and mantle. Chem Geol 145:325–394

    Article  Google Scholar 

  • Pyle JM, Spear FS, Rudnick RL, McDonough WF (2001) Monazite–xenotime–garnet equilibrium in metapelites and a new monazite–garnet thermometer. J Petrol 42:2083–2107

    Article  Google Scholar 

  • Rapp JF, Klemme S, Butler IB, Harley SL (2010) Extremely high solubility of rutile in chloride and fluoride-bearing metamorphic fluids: an experimental investigation. Geol 38:323–326

    Article  Google Scholar 

  • Ronov AB, Migdisov AA, Lobach-Zhuchenko SB (1977) Regional metamorphism and sediment composition evolution. Geochem Inter 14:90–110

    Google Scholar 

  • Roser BP, Nathan S (1997) An evaluation of elemental mobility during metamorphism of a turbidite sequence (Greenland Group, New Zealand). Geol Mag 134:219–234

    Article  Google Scholar 

  • Rubatto D, Regis D, Hermann J, Boston K, Engi M, Beltrando M, McAlpine SRB (2011) Yo–yo subduction recorded by accessory minerals in the Italian Western Alps. Nat Geosci 4:338–342

    Article  Google Scholar 

  • Sandiford M, Fraser G, Arnold J, Foden J, Farrow T (1995) Some causes and consequences of high-temperature, low-pressure metamorphism in the eastern Mt Lofty Ranges, South Australia. Aust J Earth Sci 42:233–240

    Article  Google Scholar 

  • Schwarcz HP (1966) Chemical and mineralogic variations in an arkostic quartzite during progressive burial regional metamorphism. Geol Soc Am Bul 77:509–532

    Article  Google Scholar 

  • Seward TM, Barnes HL (1997) Metal transport by hydrothermal ore fluids. In: Barnes HL (ed) Geochemistry of hydrothermal ore deposits. Wiley, New York, pp 453–486

    Google Scholar 

  • Shaw DM (1954) Trace elements in pelitic rocks I, II. Geol Soc Am Bull 65:1151–1167

    Article  Google Scholar 

  • Siahcheshm K, Calagari AA, Abedini A, Lentz DR (2012) Halogen signatures of biotites from the Maher-Abad porphyry copper deposit, Iran. Characterization of volatiles in syn- to post-magmatic hydrothermal fluids. Inter Geol Rev 54:1353–1368

    Article  Google Scholar 

  • Spandler C, Pirard C (2013) Element recycling from subduction slabs to arc crust: a review. Lithos 170–171:208–223

    Article  Google Scholar 

  • Spandler C, Hermann J, Arculus R, Mavrogenes J (2003) Redistribution of trace elements during prograde metamorphism from lawsonite blueschist to eclogite facies; implications for deep subsduction-zone processes. Contrib Mineral Petrol 146:205–222

    Article  Google Scholar 

  • Spear FS (2010) Monazite-allanite phase relations in metapelites. Chem Geol 279:55–62

    Article  Google Scholar 

  • Swan ARH, Sandilands M (1995) Introduction to geological data analysis. Blackwell Science, Oxford 446 pp

    Google Scholar 

  • Taylor SR, McLennan SM (1985) The continental crust: its composition and evolution. Blackwell, Oxford 312 pp

    Google Scholar 

  • Tischendorf G, Förster H-J, Gottesmann B (2001) Minor- and trace-element composition of trioctahedral micas: a review. Mineral Mag 65:249–276

    Article  Google Scholar 

  • Turner S, Haines P, Foster D, Powell R, Sandiford M, Offler R (2009) Did the Delamarian Orogeny start in the Neoproterozoic? J Geol 117:575–583

    Article  Google Scholar 

  • Wing BA, Ferry JM, Harrison TM (2003) Prograde destruction and formation of monazite and allanite during contact and regional metamorphism of pelites: petrology and geochronology. Contrib Mineral Petrol 145:228–250

    Article  Google Scholar 

  • Wodzicki A (1971) Migration of trace elements during contact metamorphism in the Santa Rosa Range, Nevada, and its bearing on the origin of ore deposits associated with granitic intrusions. Mineral Deposita 6:49–64

    Article  Google Scholar 

  • Yang P, Rivers T (2000) Trace element partitioning between coexisting biotite and muscovite from metamorphic rocks, Western Labrador: structural, compositional and thermal controls. Geochim Cosmochim Acta 64:1451–1472

    Article  Google Scholar 

  • Yardley BWD (1989) An Introduction to Metamorphic Petrology. Longman Scientific & Technical, New York

    Google Scholar 

  • Yardley BWD (2009) The role of water in crustal evolution. J Geol Soc 166:585–600

    Article  Google Scholar 

  • Yardley BWD, Cleverley JS (2015) The role of metamorphic fluids in the formation of ore deposits. In: Jenkin et al. (eds) Ore deposits in an evolving earth. Geol Soc London Spec Publication 393:117–134

  • Zhu C, Sverjensky DA (1991) Partitioning of F-Cl-OH between minerals in hydrothermal fluids. Geochim Cosmochim Acta 55:1837–1858

    Article  Google Scholar 

  • Zhu C, Sverjensky DA (1992) F-Cl-OH partitioning between biotite and apatite. Geochim Cosmochim Acta 56:3435–3467

    Article  Google Scholar 

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Acknowledgements

We thank Kevin Blake, Yi Hu and Shane Askew from the Advanced Analytical Centre, JCU, for assistance with EPMA and LA-ICP-MS analyses. We thank the referees, Iain Pitcairn and Fernando Bea for their numerous suggestions for improvement to the manuscript. This work was funded by the Australian Research Council (DP 1095280).

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  1. Johannes Hammerli

    Present address: Centre for Exploration Targeting, School of Earth and Environment, The University of Western Australia, Perth, Australia

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  1. Economic Geology Research Centre (EGRU), Department of Earth and Oceans, College of Science Technology and Engineering, James Cook University, Townsville, 4811, Australia

    Johannes Hammerli, Carl Spandler & Nicholas H. S. Oliver

  2. Holcombe Coughlin Oliver, Consultants, PO Box 3533, Hermit Park, 4812, Australia

    Nicholas H. S. Oliver

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Hammerli, J., Spandler, C. & Oliver, N.H.S. Element redistribution and mobility during upper crustal metamorphism of metasedimentary rocks: an example from the eastern Mount Lofty Ranges, South Australia. Contrib Mineral Petrol 171, 36 (2016). https://doi.org/10.1007/s00410-016-1239-7

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