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Trace element and isotope constraints on crustal anatexis by upwelling mantle melts in the North Atlantic Igneous Province: an example from the Isle of Rum, NW Scotland

Published online by Cambridge University Press:  27 February 2009

ROMAIN MEYER
Affiliation:
Geo-Instituut, Katholieke Universiteit Leuven, Celestijnenlaan 200E, B-3001 Leuven-Heverlee, Belgium
GRAEME R. NICOLL
Affiliation:
Department of Geology, University of Dublin, Trinity College, Dublin 2, Ireland
JAN HERTOGEN*
Affiliation:
Geo-Instituut, Katholieke Universiteit Leuven, Celestijnenlaan 200E, B-3001 Leuven-Heverlee, Belgium
VALENTIN R. TROLL
Affiliation:
Department of Geology, University of Dublin, Trinity College, Dublin 2, Ireland
ROBERT M. ELLAM
Affiliation:
Scottish Universities Environmental Research Centre, Rankine Ave., East Kilbride G75 0QF, UK
C. HENRY EMELEUS
Affiliation:
Department of Earth Sciences, University of Durham, Durham DH1 3LE, UK
*
Author for correspondence: [email protected]

Abstract

Sr and Nd isotope ratios, together with lithophile trace elements, have been measured in a representative set of igneous rocks and Lewisian gneisses from the Isle of Rum in order to unravel the petrogenesis of the felsic rocks that erupted in the early stages of Palaeogene magmatism in the North Atlantic Igneous Province (NAIP). The Rum rhyodacites appear to be the products of large amounts of melting of Lewisian amphibolite gneiss. The Sr and Nd isotopic composition of the magmas can be explained without invoking an additional granulitic crustal component. Concentrations of the trace element Cs in the rhyodacites strongly suggests that the gneiss parent rock had experienced Cs and Rb loss prior to Palaeogene times, possibly during a Caledonian event. This depletion caused heterogeneity with respect to 87Sr/86Sr in the crustal source of silicic melts. Other igneous rock types on Rum (dacites, early gabbros) are mixtures of crustal melts and and primary mantle melts. Forward Rare Earth Element modelling shows that late stage picritic melts on Rum are close analogues for the parent melts of the Rum Layered Suite, and for the mantle melts that caused crustal anatexis of the Lewisian gneiss. These primary mantle melts have close affinities to Mid-Oceanic Ridge Basalts (MORB), whose trace element content varies from slightly depleted to slightly enriched. Crustal anatexis is a common process in the rift-to-drift evolution during continental break-up and the formation of Volcanic Rifted Margins systems. The ‘early felsic–later mafic’ volcanic rock associations from Rum are compared to similar associations recovered from the now-drowned seaward-dipping wedges on the shelf of SE Greenland and on the Vøring Plateau (Norwegian Sea). These three regions show geochemical differences that result from variations in the regional crustal composition and the depth at which crustal anatexis took place.

Type
Original Article
Copyright
Copyright © Cambridge University Press 2009

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Footnotes

§

Department of Earth Sciences, Uppsala Universitet, Villavägen 16, SE-752 36 Uppsala, Sweden

References

Bailey, E. B. 1945. Tertiary igneous tectonics of Rhum, Inner Hebrides. Quarterly Journal of the Geological Society of London 100, 165–91.CrossRefGoogle Scholar
Baxter, A. N. 1987. Petrochemistry of late Palaezoic alkali lamprophyre dykes from N Scotland. Transactions of the Royal Society Edinburgh: Earth Sciences 77, 267–77.CrossRefGoogle Scholar
Carter, S. R., Evensen, N. M., Hamilton, P. J. & O'Nions, R. K. 1978. Neodymium and strontium isotopic evidence for crustal contamination of continental volcanics. Science 202, 743–7.CrossRefGoogle ScholarPubMed
Coffin, M. F. & Eldholm, O. 2005. Large igneous provinces. In Encyclopedia of Geology (eds Selley, R. C., Cocks, R. & Plimer, I. R.), pp. 315–23. Oxford: Elsevier.CrossRefGoogle Scholar
Dickin, A. P. 1981. Isotope geochemistry of Tertiary igneous rocks from the Isle of Skye, NW Scotland. Journal of Petrology 22, 155–89.CrossRefGoogle Scholar
Dunham, A. C. 1968. The felsites, granophyre, explosion breccias and tuffisites of the north-eastern margin of the Tertiary igneous complex of Rhum Inverness-shire. Journal of the Geological Society, London 123, 327–52.CrossRefGoogle Scholar
Eldholm, O., Gladczenko, T. P., Skogseid, J. & Planke, S. 2000. Atlantic volcanic margins: a comparative study. In Dynamics of the Norwegian Margin (ed. Nøttvedt, A.), pp. 411–28. Geological Society of London, Special Publication no. 167.Google Scholar
Eldholm, O., Thiede, J. & Taylor, E. 1987. Proceedings of the Ocean Drilling Program, Initial Reports, vol. 104. College Station, TX (Ocean Drilling Program).CrossRefGoogle Scholar
Emeleus, C. H. 1997. Geology of Rum and the adjacent islands. Memoir of the British Geological Survey, Scotland (Sheet 60).Google Scholar
Emeleus, C. H. & Bell, B. R. 2005. British Regional Geology: the Palaeogene volcanic districts of Scotland (4th edition). Nottingham: British Geological Survey.Google Scholar
Fitton, J. G., Larsen, L. M., Saunders, A. D., Hardarson, B. S. & Kempton, P. D. 2000. Palaeogene continental to oceanic magmatism on the SE Greenland continental margin at 63°N: a review of the results of Ocean Drilling Program Legs 152 and 163. Journal of Petrology 41, 951–66.CrossRefGoogle Scholar
Geldmacher, J., Haase, K. M., Devey, C. W. & Garbe-Schönberg, C. D. 1998. The petrogenesis of Tertiary cone-sheeets in Ardnamurchan NW Scotland: petrological and geochemical contraints on crustal contamination and partial melting. Contributions to Mineralogy and Petrology 131, 196209.CrossRefGoogle Scholar
Gibson, S. A. 1991. The geochemistry of the Trotternish sills, Isle of Skye: crustal contamination in the British Tertiary Volcanic Province. Journal of the Geological Society, London 147, 1071–81.CrossRefGoogle Scholar
Govindaraju, K. 1995. 1995 working values with confidence limits for twenty-six CRPG, ANRT and IWG-GIT geostandards. Geostandards Newsletter (Special Issue July 1995) 19, 132.CrossRefGoogle Scholar
Hamilton, M. A., Pearson, D. G., Thompson, R. N., Kelley, S. P. & Emeleus, C. H. 1998. Rapid eruption of Skye lavas inferred from precise U–Pb and Ar–Ar dating of the Rum and Cuillin plutonic complexes. Nature 394, 260–3.CrossRefGoogle Scholar
Holness, M. B. 1999. Contact metamorphism and anatexis of Torridonian arkose by minor intrusions of the Rum Igneous Complex, Inner Hebrides, Scotland. Geological Magazine 136, 527–42.CrossRefGoogle Scholar
Holness, M. B. & Isherwood, C. E. 2003. The aureole of the Rum Tertiary Igneous Complex, Scotland. Journal of the Geological Society, London 160 1527.CrossRefGoogle Scholar
Kelley, S. P., Reddy, S. M. & Maddock, R. 1994. Laser-probe 40Ar/39Ar investigation of a pseudotachylyte and its host rock from the Outer Isles thrust, Scotland. Geology 22, 443–6.2.3.CO;2>CrossRefGoogle Scholar
Kerrich, R., La Tour, T. E. & Willmore, L. 1984. Fluid participation in deep fault zones: evidence from geological, geochemical, and 18O/16O relations. Journal of Geophysical Research 89, 4331–43.CrossRefGoogle Scholar
Kinny, P. D., Friend, C. R. L. & Love, G. J. 2005. Proposal for a terrane-based nomenclature for the Lewisian Gneiss Complex of NW Scotland. Journal of the Geological Society, London 162, 175–86.CrossRefGoogle Scholar
Mahood, G. & Hildreth, W. 1983. Large partition coefficients for trace elements in high-silica rhyolites. Geochimica et Cosmochimica Acta 47, 1130.CrossRefGoogle Scholar
Manning, C. E. 2004. The chemistry of subduction-zone fluids. Earth and Planetary Science Letters 74, 116.CrossRefGoogle Scholar
Menzies, M. A., Klemperer, S., Ebinger, C. & Baker, J. 2002. Characteristics of volcanic rifted margins. In Volcanic Rifted Margins (eds Menzies, M. A., Klemperer, S., Ebinger, C. & Baker, J.), pp. 114. Geological Society of America, Special Paper no. 362.CrossRefGoogle Scholar
Meyer, R., Hertogen, J., Pedersen, R.-B., Viereck-Götte, L. & Abratis, M. 2009. Interaction of mantle derived melts with crust during the emplacement of the Vøring Plateau, N.E. Atlantic. Marine Geology, in press.CrossRefGoogle Scholar
Meyer, R., Van Wijk, J. & Gernigon, L. 2007. The North Atlantic Igneous Province: A review of models for its formation. In Plates, Plumes, and Planetary Processes (eds Foulger, G. R. & Jurdy, D. M.), pp. 525–52. Geological Society of America, Special Paper no. 430.CrossRefGoogle Scholar
Neumann, H., Mead, J. & Vitaliano, C. J. 1954. Trace element variation during fractional crystallization as calculated from the distribution law. Geochimica et Cosmochimica Acta 6, 90–9.CrossRefGoogle Scholar
Palacz, Z. A. 1985. Sr–Nd–Pb isotopic evidence for crustal contamination in the Rhum intrusion. Earth and Planetary Science Letters 74 (1), 3544.CrossRefGoogle Scholar
Palacz, Z. A. & Tait, S. R. 1985. Isotopes and geochemical investigation of unit 10 from the Eastern Layered Series of the Rhum Intrusion, Northwest Scotland. Geological Magazine 122, 485–90.CrossRefGoogle Scholar
Park, R. G., Stewart, A. D. & Wright, D. T. 2002. The Hebridean Terrane. In The Geology of Scotland (ed. Trewin, N. W.), pp. 4580. London: Geological Society.Google Scholar
Rudnick, R. L. & Gao, S. 2003. The Composition of the Continental Crust. In The Crust (ed. Rudnick, R. L.), pp. 164. Oxford: Elsevier-Pergamon.Google Scholar
Saunders, A. D., Fitton, J. G., Kerr, A. C., Norry, M. J. & Kent, R. W. 1997. The North Atlantic Igneous Province. In Large Igneous Provinces: Continental, Oceanic and Planetary Volcanism (eds Mahoney, J. J. & Coffin, M. F.), pp. 4593. American Geophysical Union, Geophysical Monograph no. 100.Google Scholar
Shaw, D. M. 1970. Trace element fractionation during anatexis. Geochimica et Cosmochimica Acta 34, 237–43.CrossRefGoogle Scholar
Spandler, C., Mavrogenes, J. & Hermann, J. 2007. Experimental constraints on element mobility from subducted sediments using high-P synthetic fluid/melt inclusions. Chemical Geology 239, 228–49.CrossRefGoogle Scholar
Sun, S. S. & McDonough, W. F. 1989. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. In Magmatism in the ocean basins (eds Saunders, A. D. & Norry, M. J.), pp. 313–45. Geological Society of London, Special Publication no. 42.Google Scholar
Tepley, F. J. & Davidson, J. P. 2003. Mineral-scale Sr-isotope constraints on magma evolution and chamber dynamics in the Rum layered intrusion, Scotland. Contributions to Mineralogy and Petrology 145, 628–41.CrossRefGoogle Scholar
Thirlwall, M. F. & Jones, N. W. 1983. Isotope geochemistry and contamination mechanics of Tertiary lavas from Skye, Northwest Scotland. In Continental Basalts and Mantle Xenoliths (eds Hawkesworth, C. J. & Norry, M. J.), pp. 186208. Nantwich, Cheshire, UK: Shiva Publishing Limited.Google Scholar
Thompson, R. N., Dickin, A. P., Gibson, I. L. & Morrison, M. A. 1982. Elemental fingerprints of isotopic contamination of Hebridean Palaeocene mantle-derived magmas by Archean sial. Contributions to Mineralogy and Petrology 79, 159–68.CrossRefGoogle Scholar
Thompson, R. N., Morrison, M. A., Dickin, A. P., Gibson, I. L. & Harmon, R. S. 1986. Two contrasting styles of interaction between basic magmas and continental crust in the British Tertiary Volcanic Province. Journal of Geophysical Research 91, 5985–97.CrossRefGoogle Scholar
Tilley, C. E. 1944. A note on the gneisses of Rum. Geological Magazine 81, 129–31.CrossRefGoogle Scholar
Troll, V. R., Donaldson, C. H. & Emeleus, C. H. 2004. Pre-eruptive magma mixing in ash-flow deposits in the Tertiary Rum Igneous Centre, Scotland. Contributions to Mineralogy and Petrology 147, 722–39.CrossRefGoogle Scholar
Troll, V. R., Emeleus, C. H. & Donaldson, C. H. 2000. Caldera formation in the Rum central igneous complex, Scotland. Bulletin of Volcanology 62, 301–17.CrossRefGoogle Scholar
Troll, V. R., Nicoll, G. R., Emeleus, C. H. & Donaldson, C. H. 2008. Dating the onset of volcanism at the Rum Igneous Centre, NW Scotland. Journal of the Geological Society, London 165, 651–9.CrossRefGoogle Scholar
Upton, B. G. J., Skovgaard, A. C., McClurg, J., Kirstein, L., Cheadle, M., Emeleus, C. H., Wadworth, W. J. & Fallick, A. E. 2002. Picritic magmas and the Rum ultramafic complex, Scotland. Geological Magazine 139, 437–52.CrossRefGoogle Scholar
Viereck, L. G., Hertogen, J., Parson, L. M., Morton, A. C., Love, D. & Gibson, I. L. 1989. Chemical stratigraphy and petrology of the Vøring Plateau tholeiitic lavas and interlayered volcaniclastic sediments at ODP Hole 642E. In Proceedings of the Ocean Drilling Program, Scientific Results, vol. 104 (eds Eldholm, O., Thiede, J., Taylor, E. et al. ), pp. 367–96. College Station, Texas.Google Scholar
Viereck, L. G., Taylor, P. N., Parson, L. M., Morton, A. C., Hertogen, J. & the ODP Leg 104 Scientific Party. 1988. Origin of the Palaeogene Vøring plateau volcanic sequence. In Early Tertiary Volcanism and the Opening of the NE Atlantic (eds Morton, A. C. & Parson, L. M.), pp. 6983. Geological Society of London, Special Publication no. 39.Google Scholar
Weaver, B. L. & Tarney, J. 1981. Lewisian gneiss geochemistry and Archean crustal development models. Earth and Planetary Science Letters 55, 171–80.CrossRefGoogle Scholar
Wood, D. A. 1980. The application of a Th–Hf–Ta diagram to problems of tectonomagmatic classification and to establishing the nature of crustal contamination of basaltic lavas of the British Tertiary Volcanic Province. Earth and Planetary Science Letters 50, 1130.CrossRefGoogle Scholar
Zack, T. & John, T. 2007. An evaluation of reactive fluid flow and trace element mobility in subducting slabs. Chemical Geology 239, 199216.CrossRefGoogle Scholar