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Mineral-scale Sr isotope variation in plutonic rocks — a tool for unravelling the evolution of magma systems

Published online by Cambridge University Press:  11 January 2017

Jon P. Davidson
Affiliation:
Department of Earth Sciences, University of Durham, South Road, Durham DH1 3LE, UK, e-mail: [email protected]
Laura Font
Affiliation:
Department of Earth Sciences, University of Durham, South Road, Durham DH1 3LE, UK, e-mail: [email protected]
Bruce L. A. Charlier
Affiliation:
Department of Earth Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK
Frank J. Tepley III
Affiliation:
College of Oceanic and Atmospheric Sciences, 104 COAS Admin Building, Oregon State University, Corvallis, OR 97331-5503, USA

Abstract

Isotope ratios of elements such as Sr, Nd, Pb and Hf can be used as tracers of magmatic sources and processes. Analytical capabilities have evolved so that isotope ratios can now be analysed in situ, and isotopic tracers can therefore be used within single minerals to track the changing magmatic environment in which a given mineral grew. This contribution shows that Sr isotope ratios in feldspars that make up plutonic rocks will typically preserve initial isotopic variations, provided precise and accurate age corrections can be applied. Variations in initial isotope ratio can give a core-to-rim record of magmatic evolution and can be used to diagnose open system events such as contamination and magma recharge and mixing.

New single grain Sr isotope data are presented from the Dais Intrusion, Antarctica, which reflect an open system origin for the crystals. The crystal cargo appears to be aggregated and assembled during transport and emplacement. This model, as opposed to a magma body crystallising post emplacement, may be more applicable to plutonic rocks in general, and is testable using the in situ isotopic determination methods described here.

Type
Research Article
Copyright
Copyright © The Royal Society of Edinburgh 2008

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References

Bedard, J.H., Sparks, R.S.J., Renner, R., Cheadle, M.J. & Hallworth, M.A. 1988. Peridotite sills and metasomatic gabbros in the Eastern Layered Series of the Rhum Complex. Journal of the Geological Society, London 145, 207-24.Google Scholar
Caunt, S.L. 1987. Igneous and metamorphic processes in the Shap Granite and its aureole. Unpublished PhD Thesis, University of Leeds, UK.Google Scholar
Charlier, B.L.A., Wilson, C.J.N., Lowenstern, J.B., Blake, S., VanCalsteren, P.W. & Davidson, J.P. 2005. Magma Generation at a Large, Hyperactive Silicic Volcano (Taupo, New Zealand) Revealed by U-Th and U-Pb Systematics in Zircons. Journal of Petrology 46, 3-32.CrossRefGoogle Scholar
Charlier, B.L.A., Ginibre, C., Morgan, D., Noweli, G. M., Pearson, G., Davidson, J.P. & Ottley, C.J. 2006. Methods for the microsampling and analysis of strontium and rubidium isotopes at single crystal scale for petrological and geochronological applications. Chemical Geology 232, 114-33.CrossRefGoogle Scholar
Charlier, B.L.A., Bachman, O., Davidson, J.P., Dungan, M.A. & Morgan, D.J. 2007. The upper crustal evolution of a large silicic magma body: Evidence from crystal-scale Rb-Sr isotopic heterogeneities in the Fish Canyon magmatic system, Colorado. Journal of Petrology 48, 1875-94.Google Scholar
Cherniak, D.J. & Watson, E.B. 1994. A study of strontium diffusion in plagioclase using Rutherford backscattering spectroscopy. Geochimica et Cosmochimica Acta 58, 5179-90.Google Scholar
Clynne, M.A. 1999. Complex magma mixing origin for multiple volcanic lithologies erupted in 1915, from Lassen Peak, California. Journal of Petrology 40, 105-32.Google Scholar
Cox, R.A., Dempster, T.J., Bell, B.R. & Rogers, G. 1996. Crystallization of the Shap Granite: evidence from zoned K-feldspar megacrysts. Journal of the Geological Society, London 153, 625-35.CrossRefGoogle Scholar
Davidson, J.P., De Silva, S.L., Holden, P. & Halliday, A.N. 1990. Small scale disequilibrium in a magmatic inclusion and its’ more silicic host. Journal of Geophysical Research 95, 17 661-75.CrossRefGoogle Scholar
Davidson, J.P., Tepley, F.J. III & Knesel, K.M. 1998. Crystal isotope stratigraphy; A method for constraining magma differentiation pathways. Eos 79 (15), 185, 189, 193.CrossRefGoogle Scholar
Davidson, J.P., Tepley, F.J. III, Palacz, Z. & Main, S. 2001, Magma recharge, contamination and residence times revealed by in situ laser ablation isotopic analysis of feldspar in volcanic rocks Earth and Planetary Science Letters 182, 427-42.Google Scholar
Davidson, J.P., Chartier, B.L.A., Hora, J.M. & Perlroth, R. 2005. Mineral isochrons and isotopic fingerprinting: Pitfalls and promises. Geology 33, 29-32.Google Scholar
Davidson, J.P. & Tepley, F.J. III. 1997. Recharge in volcanic systems; evidence from isotope profiles of phenocrysts. Science 275, 826-9.Google Scholar
Dungan, M.A. & Davidson, J.P. 2004. Partial assimilative recycling of the mafic plutonic roots of arc volcanoes: An example from the Chilean Andes. Geology 32, 773-6.Google Scholar
Eichelberger, J.C. 1978. Andesitic volcanism and crustal evolution. Nature 275, 21-7.Google Scholar
Elliot, D.H., Fleming, T.H., Kyle, P.R. & Foland, K.A. 1999. Long-distance transport of magmas in the Jurassic Ferrar Large Igneous Province, Antarctica. Earth and Planetary Science Letters 167, 89-104.Google Scholar
Emeleus, C.H., Cheadle, M.J., Hunter, R.H., Upton, B.G.J. & Wadsworth, W.J. 1996. The Rum layered suite. In Cawthorn, R.G. (ed.) Layered Intrusions, Developments in Petrology 15, 403-39. Amsterdam: Elsevier Science B.V. CrossRefGoogle Scholar
Emeleus, C.H. and Bell, B.R. 2005. British regional geology: the Palaeogene volcanic districts of Scotland (Fourth edition). Key-worth, Nottingham: British Geological Survey.Google Scholar
Gagnevin, D., Daly, J.S., Poli, G. & Morgan, D. 2005a. Microchemi-cal and Sr isotopic investigation of zoned K-feldspar megacrysts: insights into the petrogenesis of a plutonic system and disequilibrium processes during crystal growth. Journal of Petrology 46, 1689-724.CrossRefGoogle Scholar
Gagnevin, D., Daly, J.S., Waight, T.E., Morgan, D. & Poli, G. 2005b. Pb isotopic zoning of K-feldspar megacrysts determined by laser ablation multiple-collector ICP-MS: insights into granite petrogenesis. Geochimica et Cosmochimica Acta 69, 1899-915.Google Scholar
Ganguly, J. & Ruiz, J. 1986. Time-temperature relation of mineral isochrons: a thermodynamic model and illustrative examples for the Rb-Sr system. Earth and Planetary Science Letters 81, 338-48.CrossRefGoogle Scholar
Giletti, B.J. 1991. Rb and Sr diffusion in alkali feldspars, with implications for cooling histories of rocks. Geochimica et Cosmochimica Acta 55, 1331-43.CrossRefGoogle Scholar
Henderson, P. & Gijbels, R. 1976. Trace element indicators of the genesis of the Rhum layered intrusion, Inner Hebrides. Scottish Journal of Geology 12, 325-33.CrossRefGoogle Scholar
Knesel, K.M., Davidson, J.P. & Duffield, W.A. 1999. Open-system Evolution of Silicic Magma by Assimilation Followed by Recharge: Evidence from Sr Isotopes in Sanidine Phenocrysts, Taylor Creek Rhyolite, NM. Journal of Petrology 40, 773-86.CrossRefGoogle Scholar
Marsh, B. 2004. A Magmatic Mush Column Rosetta Stone: The McMurdo Dry Valleys of Antarctica. Eos 85 (47), 497, 502.CrossRefGoogle Scholar
Palacz, Z.A. 1984. Isotopie and geochemical evidence for the evolution of a cyclic unit in the Rhum Intrusion, north-west Scotland. Nature 307, 618-20.Google Scholar
Perlroth, R. 2002. An investigation of crystal transfer between melts. Unpublished MS Thesis, University of California, Los Angeles.Google Scholar
Petford, N., Cruden, A.R., McCaffrey, K.J.W. & Vigneresse, J.-L. 2000. Granite magma formation, transport and emplacement in the Earth’s crust. Nature 408, 669-73.CrossRefGoogle ScholarPubMed
Pidgeon, R.T. & Aftalion, M. 1978. Co-genetic and inherited zircon U-Pb systems in granites. Palaeozoic granites of Scotland and England. In Bowes, D.R. and Leake, B.E. (eds) Geological Journal Special Issue 10, 183-220. London: The Geological Society.Google Scholar
Ramos, F.C., Wolff, J.A. & Tollstrup, D.L. 2004. Measuring 87Sr/86Sr variations in minerals and groundmass from basalts using LA-MC-ICPMS. Chemical Geology 211, 135-58.Google Scholar
Ramos, F.C. & Reid, M.R. 2005. Distinguishing Melting of Heterogeneous Mantle Sources from Crustal Contamination: Insights from Sr Isotopes at the Phenocryst Scale, Pisgah Crater, California. Journal of Petrology 46, 999-1012.Google Scholar
Reddy, S.M., Kelley, S.P. & Wheeler, J. 1996. A 40Arl39 Ar laser probe study of micas from the Seisa zone, Italian Alps: Implications for metamorphic and deformation histories. Journal of Metamorphic Geology 14, 493-508.Google Scholar
Rundle, C. C. 1992. Review and assessment of isotopic ages from the English Lake District. British Geological Survey, Onshore Geology Series, Technical Report WA/92/38.Google Scholar
Siebel, W., Reitter, E., Wenzel, T. & Blaha, U. 2005. Sr isotope systematics of K-feldspars in plutonic rocks revealed by Rb-Sr microdrilling technique. Chemical Geology 222, 183-99.Google Scholar
Sneeringer, M., Hart, S.R. & Shimizu, N. 1984. Strontium and samarium diffusion in diopside. Geochimica et Cosmochimica Acta 48, 1589-608.CrossRefGoogle Scholar
Tepley, F.J. III, Davidson, J.P. & Clynne, M.A. 1999. Magmatic Interactions as Recorded in Plagioclase Phenocrysts of Chaos Crags, Lassen Volcanic Center, California. Journal of Petrology 40, 787-806.Google Scholar
Tepley, F.J. III, Davidson, J.P. Tilling, R.I. & Arth, J.G. 2000. Magma mixing, recharge and eruption histories recorded in plagioclase phenocrysts from El Chichón volcano, Mexico. Journal of Petrology 41, 1397-411.CrossRefGoogle Scholar
Tepley, F.J. III, & 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, 628-11.Google Scholar
Vernon, R.H. 1984. Microgranular enclaves in granites - globules of hybrid magma quenched in a plutonic environment. Nature 309, 438-9.Google Scholar
Vernon, R.H. 1986. K-feldspar megacrysts in granites - phenocrysts not porphyroblasts. Earth Science Reviews 23, 1-63.CrossRefGoogle Scholar
Waight, T.E., Maas, R. & Nicholls, I.A. 2000. Fingerprinting feldspar phenocrysts using crystal isotopic composition stratigraphy: implications for crystal transfer and magma mingling in S-type granites. Contributions to Mineralogy and Petrology 139, 227-39.CrossRefGoogle Scholar
Waight, T.E., Baker, J. & Peate, D. 2002. Sr isotope ratio measurements by double-focusing MC-ICPMS: techniques, observations and pitfalls. International Journal of Mass Spectrometry 221, 229-14.Google Scholar