Hostname: page-component-848d4c4894-ndmmz Total loading time: 0 Render date: 2024-05-04T10:53:35.167Z Has data issue: false hasContentIssue false
  • English
  • Français

A geochemical and Sr-Nd-O isotopic study of the Proterozoic Eriksfjord Basalts, Gardar Province, South Greenland: Reconstruction of an OIB signature in crustally contaminated rift-related basalts

Published online by Cambridge University Press:  05 July 2018

R. Halama ,
T. Wenzel ,
B. G. J. Upton ,
W. Siebel  and
G. Markl
R. Halama
Affiliation:
Universität Tübingen, Institut für Geowissenschaften, Wilhelmstr. 56, D-72074 Tübingen, Germany
T. Wenzel
Affiliation:
Universität Tübingen, Institut für Geowissenschaften, Wilhelmstr. 56, D-72074 Tübingen, Germany
B. G. J. Upton
Affiliation:
Department of Geology and Geophysics, The University of Edinburgh, West Mains Road, Edinburgh EH9 3JW, UK
W. Siebel
Affiliation:
Universität Tübingen, Institut für Geowissenschaften, Wilhelmstr. 56, D-72074 Tübingen, Germany
G. Markl*
Affiliation:
Universität Tübingen, Institut für Geowissenschaften, Wilhelmstr. 56, D-72074 Tübingen, Germany
*
* E-mail: markl@uni-tuebingen.de
Get access Rights & Permissions [Opens in a new window]

Abstract

Basalts from the volcano-sedimentary Eriksfjord Formation (Gardar Province, South Greenland) were erupted at around 1.2 Ga into rift-related graben structures. The basalts have compositions transitional between tholeiite and alkaline basalt with MgO contents <7 wt.% and they display LREE-enrichment relative to a chondritic source. Most of the trace element and REE characteristics are similar to those of basalts derived from OIB-like mantle sources. Initial 87Sr/86Sr ratios of clinopyroxene separates range from 0.70278 to 0.70383 and initial ϵNd values vary from –3.2 to +2.1. The most unradiogenic samples overlap with the field defined by carbonatites of similar age and can be explained by mixing of isotopically depleted and enriched mantle components. Using AFC modelling equations, the Sr-Nd isotope data of the more radiogenic basalts can successfully be modelled by addition of <5% lower crustal granulite-facies gneisses as contaminants. δ18Ov-smow values of separated clinopyroxene range from +5.2 to +6.0% and fall within the range of typical mantle-derived rocks. However, up to 10% mixing with an average lower crustal component are permitted by the data.

Keywords

geochemistrySr-Nd-O isotopesGardar ProvincebasaltGreenland.
Type
Research Article
Information
Mineralogical Magazine , Volume 67 , Issue 5 , October 2003 , pp. 831 - 853
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2003

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Andersen, T. (1997) Age and petrogenesis of the Qassiarsuk carbonatite-alkaline silicate volcanic complex in the Gardar rift, South Greenland. Mineralogical Magazine, 61, 499—513.CrossRefGoogle Scholar
Armstrong, J.T. (1991) Quantitative elemental analysis of individual microparticles with electron beam instruments. Pp. 261—315 in. Electron Probe Quantitation, (Heinrich, K.F.J. and Newbury, D.E., editors). Plenum Press, New York and London.CrossRefGoogle Scholar
Arndt, N.T. and Christensen, U. (1992) The role of lithospheric mantle in continental flood volcanism: Thermal and geochemical constraints. Journal of Geophysical Research, 97, 10967—10981.CrossRefGoogle Scholar
Baker, J.A., Menzies, M.A., Thirlwall, M.F. and Macpherson, C.G. (1997) Petrogenesis of Quaternary Intraplate Vocanism, Sana’a, Yemen: Implications for Plume-Lithosphere Interaction and Polybaric Melt Hybridization. Journal of Petrology, 38, 1359—1390.CrossRefGoogle Scholar
Baker, J.A., MacPherson, C.G., Menzies, M.A., Thirlwall, M.F., Al-Kadasi, M. and Mattey, D.P. (2000) Resolving crustal and mantle contributions to continental flood volcanism, Yemen; constraints from mineral oxygen isotope data. Journal of Petrology, 41, 1805—1820.CrossRefGoogle Scholar
Beard, J.S., Abitz, R.J. and Lofgren, G.E. (1993) Experimental melting of crustal xenoliths from Kilbourne Hole, New Mexico and implications for the contamination and genesis of magmas. Contributions to Mineralogy and Petrology, 115, 88—102.CrossRefGoogle Scholar
Bell, K. (2001) Carbonatites; relationships to mantle-plume activity. Geological Society of America Special Paper,, 352, 267—290.Google Scholar
Bell, K. and Blenkinsop, J. (1989) Neodymium and Strontium Isotope Geochemistry of Carbonatites. Pp. 278—300 in. Carbonatites – Genesis and Evolution, (Bell, K., editor). Unwin Hyman, London.Google Scholar
Bell, K. and Simonetti, A. (1996) Carbonat ite Magmatism and Plume Activity: Implications from the Nd, Pb and Sr Isotope Systematics of Oldoinyo Lengai. Journal of Petrology, 37, 1321—1339.CrossRefGoogle Scholar
Bell, K. and Tilton, G.R. (2001) Nd, Pb and Sr Isotopic Compositions of East African Carbonat ites: Evidence for Mantle Mixing and Plume Inhomogeneity. Journal of Petrology, 42, 1927—1945.CrossRefGoogle Scholar
Benoit, M., Polvé, M. and Ceuleneer, G. (1996) Trace element and isotopic characterization of mafic cumulates in a fossil mantle diapir (Oman ophiolite. Chemical Geology, 134, 199—214.CrossRefGoogle Scholar
Bernstein, S., Kelemen, P.B., Tegner, C., Kurz, M.D., Blusztajn, J. and Kent Brooks, C. (1998) Post- breakup basaltic magmatism along the East Greenland Tertiary rifted margin.. Earth and Planetary Science Letters, 160, 845—862.CrossRefGoogle Scholar
Boynton, W.V. (1984) Geochemistry of the rare earth elements: meteorite studies. Pp. 63—114 in: Rare Earth Element Geochemistry (Henderson, P., editor). Elsevier, Amsterdam.CrossRefGoogle Scholar
Carroll, M.R. and Wyllie, P.J. (1990) The system tonalite-H2O at 15 kbar and the genesis of calc- alkaline magmas. American Mineralogist, 75, 345—357.Google Scholar
Chauvel, C., Hofmann, A.W. and Vidal, P. (1992) HIMU-EM: The French Polynesian connection. Earth and Planetary Science Letters, 110, 99—119.CrossRefGoogle Scholar
Clayton, R.N. and Mayeda, T.K. (1963) The use of bromine pentafluoride in the extraction of oxygen from oxides and silicates for isotope analysis. Geochimica et Cosmochimica Acta, 27, 43—52.CrossRefGoogle Scholar
Coulson, I.M. and Chambers, A.D. (1996) Patterns of zonation in rare-earth-bearing minerals in nepheline syenites of the North Qôroq center, South Greenland. The Canadian Mineralogist, 34, 1163—1178.Google Scholar
Cox, K.G., Bell, J.D. and Pankhurst, R.J. (1979) The Interpretation of Igneous Rocks. George, Allen and Unwin, London.CrossRefGoogle Scholar
Cross, W., Iddings, J.P., Pirsson, L.V. and Washington, H.S. (1903) Quantitative Classification of Igneous Rocks. University of Chicago Press.Google Scholar
Dahl-Jensen, T., Thybo, T., Hopper, H. and Rosing, M. (1998) Crustal structure at the SE Greenland margin from wide-angle and normal incidence seismic data. Tectonophysics, 288, 191—198.CrossRefGoogle Scholar
DePaolo, D.J. (1981) Trace element and isotopic effects of combined wallrock assimilation and fractional crystallisation. Earth and Planetary Science Letters, 53, 189—202.CrossRefGoogle Scholar
De Paolo, D. J. (1988) Neodymium I sotope Geochemistry: An Introduction. Springer-Verlag, New York.CrossRefGoogle Scholar
Dobosi, G., Downes, H., Mattey, D. and Embey-Isztin, A. (1998) Oxygen isotope ratios of phenocrysts from alkali basalts of the Pannonian basin: Evidence for an O-isotopically homogeneous upper mantle be- neath a subduction-infl uenced area. Lithos, 42, 213—223.CrossRefGoogle Scholar
Eiler, J.M. (2001) Oxygen isotope variations of basaltic lavas and upper mantle rocks. Pp. 319—364 in: Stable Isotope Geochemistry (Valley, J.W. and Cole, D.R., editors). Reviews in Mineralogy and Geochemistry, 43. The Mineralogical Society of America, Washington D.C.CrossRefGoogle Scholar
Eiler, J.M., Farley, K.A., Valley, J.W., Hauri, E., Craig, H., Hart, S.R. and Stolper, E.M. (1997) Oxygen isotope variations in ocean island basalt phenocrysts. Geochimica et Cosmochimica Acta, 61, 2281—2293.CrossRefGoogle Scholar
Eiler, J.M., Crawford, A., Elliot, T., Farley, K.A., Valley, J.W. and Stolper, E.M. (2000a)) Oxygen isotope geochemistry of oceanic-arc lavas. Journal of Petrology, 41, 229—256.CrossRefGoogle Scholar
Eiler, J.M., Schiano, P., Kitchen, N. and Stolper, E.M. (2000b)) Oxygen-isotope evidence for recycled crust in the sources of mid-ocean-ridge basalts. Nature, 403, 530—534.CrossRefGoogle Scholar
Emeleus, C.H. and Upton, B.G.J. (1976) The Gardar period in southern Greenland. Pp. 152—181 in: Geology of Greenland (Escher, A. and Watt, W.S., editors). Geological Survey of Greenland, Copenhagen.Google Scholar
Fitton, J.G. (1995) Coupled molybdenum and niobium depletion in continental basalts. Earth and Planetary Science Letters, 136, 715—721.CrossRefGoogle Scholar
Fitton, J.G., Saunders, A.D., Norry, M.J., Hardarson, B.S. and Taylor, R.N. (1997) Thermal and chemical structure of the Iceland plume. Earth and Planetary Science Letters, 153, 197—208.CrossRefGoogle Scholar
Floyd, P.A. and Winchester, J.A. (1975) Magma-type and tectonic setting discrimination using immobile elements. Earth and Planetary Science Letters, 27, 211—218.CrossRefGoogle Scholar
Fowler, M.B. and Harmon, R.S. (1990) The oxygen isotope composition of lower crustal granulite xenoliths. Pp. 493—506 in: Granulites and Crustal Evolution (Vielzeuf, D. and Vidal, P., editors). Kluwer Academic Publishers, Dordrecht, The Netherlands.CrossRefGoogle Scholar
Garde, A.A., Hamilton, M.A., Chadwick, B., Grocott, J. and McCaffrey, K.J.W. (2002) The Ketilidian orogen of South Greenland: geochronology, tectonics, magmatism, and fore -arc accretion during Palaeoproterozoic oblique convergence. Canadian Journal of Earth Sciences, 39, 765—793.CrossRefGoogle Scholar
Gibson, S.A., Thompson, R.N., Dickin, A.P. and Leonardos, O.H. (1995) High-Ti and Low-Ti mafic potassic magmas: key to plume-lithosphere interac- tions and continental flood-basalt genesis. Earth and Planetary Science Letters, 136, 149—165.CrossRefGoogle Scholar
Gibson, S.A., Thompson, R.N., Weska, R.K. and Dickin, A.P. (1997) Late-Cretaceous rift-related upwelling and melting of the Trinidade starting mantle-plume head beneath western Brazil. Contributions to Mineralogy and Petrology, 126, 303—314.CrossRefGoogle Scholar
Gibson, S.A., Thompson, R.N., Leonardos, O.H., Dickin, A.P. and Mitchell, J.G. (1999) The limited extent of plume-lithosphere interactions during continental flood-basalt genesis: geochemical evi- dence from Cretaceous magmatism in southern Brazil. Contributions to Mineralogy and Petrology, 137, 147—169.CrossRefGoogle Scholar
Goldstein, S.L., O’Nions, R.K. and Hamilton, P.J. (1984) A Sm-Nd isotopic study of the atmospheric dust and particulates from major river systems. Earth and Planetary Science Letters, 70, 221—236.CrossRefGoogle Scholar
Goodenough, K.M., Upton, B.G.J. and Ellam, R.M. (2002) Long-term memory of subduction processes in the lithospheric mantle: evidence from the geochemistry of basic dykes in the Gardar Province of south Greenland. Journal of the Geological Society of London, 159, 705—714.CrossRefGoogle Scholar
Harmon, R.S. and Hoefs, J. (1995) Oxygen isotope heterogeneity of the mantle deduced from global 18O systematics of basalts from different geotectonic settings. Contributions to Mineralogy and Petrology, 120, 95—114.CrossRefGoogle Scholar
Harris, C., Smith, H.S. and le Roex, A.P. (2000) Oxygen isotope composition of phenocrysts from Tristan da Cunha and Gough Island lavas: variation with fractional crystallization and evidence for assimila- tion. Contributions to Mineralogy and Petrology, 138, 164—175.CrossRefGoogle Scholar
Hart, S.R., Hauri, E.H., Oschmann, L.A. and Whitehead, J.A. (1992) Mantle plumes and entrainment: Isotopic evidence. Science, 256, 517—520.CrossRefGoogle ScholarPubMed
Hawkesworth, C.J., Kempton, P.D., Rogers, N.W., Ellam, R.M. and van Calsteren, P.W. (1990) Continental mantle lithosphere and shallow level enrichment processes in the Earth’s mantle. Earth and Planetary Science Letters, 96, 256—268.CrossRefGoogle Scholar
Heaman, L.M. and Machado, N. (1992) Timing and origin of midcontinent rift alkaline magmatism, North America: evidence from the Coldwell Complex. Contributions to Mineralogy and Petrology, 110, 289—303.CrossRefGoogle Scholar
Hofmann, A. (1997) Mantle geochemistry: the message from oceanic volcanism. Nature, 385, 219—229.CrossRefGoogle Scholar
Humphris, S.E. and Thompson, G. (1983) Geochemistry of rare earth elements in basalts from the Walvis Ridge: implications for its origin and evolution. Earth and Planetary Science Letters, 66, 223—242.CrossRefGoogle Scholar
Jacobsen, S.B. and Wasserburg, G.J. (1980) Sm-Nd isotopic evolutio n of chondrit es. Earth and Planetary Science Letters, 50, 139—155.CrossRefGoogle Scholar
Kalamarides, R.I. (1986) High-temperature oxygen isotope fractionation among the phases of Kiglapait intrusion, Labrador, Canada. Chemical Geology, 58, 303—310.Google Scholar
Larsen, J.G. (1977) Petrology of the late lavas of the Eriksfjord Formation, Gardar province, South Greenland. Bulletin Grønlands Geologiske Undersøgelse, 125, 31.pp.Google Scholar
Le Maitre, R.W., Bateman, P., Dudek, A., Keller, J., Le Bas, M.J., Sabine, P.A., Schmid, R., Sørensen, H., Streckeisen, A., Woolley, A.R. and Zanettin, B. (1989) A Classification of Igneous Rocks and Glossary of Terms. Blackwell, Oxford, UK.Google Scholar
Lightfoot, P.C., Sutcliffe, R.H. and Doherty, W. (1991) Crustal contamination identified in Keweenawan Osler Group Tholeiites, Ontario: A trace element perspective. Journal of Geology, 99, 739—760.CrossRefGoogle Scholar
Lindsley, D.H. (1983) Pyroxene thermometry. American Mineralogist, 68, 477—493.Google Scholar
Lugmair, G.W. and Marti, K. (1978) Lunar initial 143Nd/144Nd: differential evolution of the lunar crust and mantle. Earth and Planetary Science Letters, 39, 349—357.CrossRefGoogle Scholar
Mahoney, J.J. (1988) Deccan traps. Pp. 151—194 in: Continental Flood Basalts (MacDougall, J.D., editor). Kluwer Academic Publishers, Dordrecht, The Netherlands.CrossRefGoogle Scholar
Mattey, D., Lowry, D. and Macpherson, C. (1994) Oxygen isotope composition of mantle peridotite. Earth and Planetary Science Letters, 128, 231—241.CrossRefGoogle Scholar
McDonough, W.F. and Sun, S.S. (1995) The composi- tion of the Earth. Chemical Geology, 120, 223—253.CrossRefGoogle Scholar
Middlemost, E.A.K. (1989) Iron oxidation ratios, norms and the classification of volcanic rocks. Chemical Geology, 77, 19—26.CrossRefGoogle Scholar
Molzahn, M., Reisberg, L. and Wörner, G. (1996) Os, Sr, Nd, Pb, O isotope and trace element data from the Ferrar flood basalts, Antarctica: evidence for an enriched subcontinental lithospheric source. Earth and Planetary Science Letters, 144, 529—546.CrossRefGoogle Scholar
Morimoto, N., Fabrie, J., Ferguson, A.K., Ginzburg, I.V., Ross, M., Seifert, F.A., Zussman, J., Aoki, K. and Gottardi, G. (1988) Nomenclature of pyroxenes. Mineralogical Magazine, 52, 535—550.CrossRefGoogle Scholar
Nicholson, S.W., Shirey, S.B., Schulz, K.J. and Green, J.C. (1997) Rift-wide correlati on of 1.1 Ga Midcontinent rift system basalts: implications for multiple mantle sources during rift development. Canadian Journal of Earth Sciences, 34, 504—520.CrossRefGoogle Scholar
Nimis, P. and Vannucci, R. (1995) An ion microprobe study of clinopyroxenes in websteritic and mega- crystic xenoliths from Hyblean Plateau (SE Sicily, Italy): constraints on HFSE/REE/Sr fractionation at mantle depth. Chemical Geology, 124, 185—197.CrossRefGoogle Scholar
Oliveira, E.P. and Tarney, J. (1995) Petrogenesis of the Late Proterozoic Curac¸a´ mafic dyke swarm, Brazil: asthenospheric magmatism associated with conti- nental collision. Mineralogy and Petrology, 53, 27—48.CrossRefGoogle Scholar
Ormerod, D.S., Hawkesworth, C.J., Rogers, N.W., Leeman, W.P. and Menzies, M.A. (1988) Tectonic and magmatic transitions in the Western Great Basin, USA. Nature, 333, 349—353.CrossRefGoogle Scholar
Paces, J.B. and Bell, K. (1989) Non-depleted sub-continental mantle beneath the Superior Province of the Canadian Shield: Nd-Sr isotopic and trace element evidence from Midcontinent Rift basalts. Geochimica et Cosmochimica Acta, 53, 2023—2035.CrossRefGoogle Scholar
Paslick, C.R., Halliday, A.N., Davies, G.R., Mezger, K. and Upton, B.G.J. (1993) Timing of proterozoic magmatism in the Gardar Province, southern Greenland. Bulletin of the Geological Society of America, 105, 272—278.2.3.CO;2>CrossRefGoogle Scholar
Paslick, C.R., Halliday, A.N., James, D. and Dawson, J.B. (1995) Enrichment of the continental lithosphere by OIB melts: Isotopic evidence from the volcanic province of northern Tanzania. Earth and Planetary Science Letters, 130, 109—126.CrossRefGoogle Scholar
Pearce, N.J.G. and Leng, M.J. (1996) The origin of carbonatites and related rocks from the Igaliko Dyke Swarm, Gardar Province, South Greenland: field, geochemical and C-O-Sr-Nd isotope evidence. Lithos, 39, 21—40.CrossRefGoogle Scholar
Perry, F.V., Baldridge, W.S. and DePaolo, D.J. (1987) Role of asthenosphere and lithosphere in the genesis of late cenozoic basaltic rocks from the Rio Grande rift and adjacent regions of the Southwestern United States. Journal of Geophysical Research, 92, 9193—9213.CrossRefGoogle Scholar
Philpotts, A.R. (1990) Principles of Igneous and Metamorphic Petrology. Prentice Hall, New Jersey, U.S.A.Google Scholar
Piper, J.D.A., Thomas, D.N., Share, S. and Zhang Qi Rui (1999) The palaeomagnetism of (Mesoproterozoic) Eriksfjord Group red beds, South Greenland: multi- phase remagnetizat ion during the Gardar and Gre nville episode s. Geophysical Journal International, 136, 739—756.CrossRefGoogle Scholar
Poulsen, V. (1964) The sandstones of the Precambrian Eriksfjord Formation in South Greenland. Rapport Grønlands Geologiske Undersøgelse, 2, 16. pp.Google Scholar
Price, R.C., Gray, C.M., Wilson, R.E., Frey, F.A. and Taylor, S.R. (1991) The effects of weathering on rare-earth element, Y and Ba abundances in Tertiary basalts from southeastern Australia. Chemical Geology, 93, 245—265.CrossRefGoogle Scholar
Ranløv, J. and Dymek, R.F. (1991) Compositional zoning in hydrothermal aegirine from fenites in the Proterozoic Gardar Province, South Greenland. European Journal of Mineralogy, 3, 837—853.CrossRefGoogle Scholar
Reiners, P.W., Nelson, B.K. and Ghiorso, M.S. (1995) Assimilation of felsic crust by basaltic magma: thermal limits and extents of crustal contamination of mantle-derived magmas. Geology, 23, 563—566.2.3.CO;2>CrossRefGoogle Scholar
Roddick, J.C., Sullivan, R.W. and Dudas, F.ö. (1992) Precise calibration of Nd tracer isotopic composition for Sm-Nd studies. Chemical Geology, 97, 1—8.CrossRefGoogle Scholar
Rollinson, H. (1993) Using Geochemical Data: Evaluation, Presentation, Interpretation. Longman Group UK, Limited, London.Google Scholar
Rudnick, R. and Fountain, D.M. (1995) Nature and composition of the continental crust: A lower crustal perspective. Reviews of Geophysics, 33, 267—309.CrossRefGoogle Scholar
Rumble, D. and Hoering, T.C. (1994) Analysis of oxygen and sulfur isotope ratios in oxide and sulfide minerals by spot heating with a carbon dioxide laser in a fluorine atmosphrere. Accounts of Chemical Research, 27, 237—241.CrossRefGoogle Scholar
Schleicher, H., Kramm, U., Pernicka, E., Schidlowski, M., Schmidt, F., Subramanian, V., Todt, W. and Viladkar, S.G. (1998) Enriched subcontinental upper mantle beneath Southern India: Evidence from Pb, Nd, Sr and C-O isotopic studies on Tamil Nadu carbonatites. Journal of Petrology, 39, 1765—1785.CrossRefGoogle Scholar
Sharp, Z.D. (1990) A laser-based microanalytical method for the in-situ determination of oxygen isotope ratios of silicates and oxides. Geochimica et Cosmochimica Acta, 54, 1353—1357.CrossRefGoogle Scholar
Shirey, S.B., Klewin, K.W., Berg, J.H. and Carlson, R.W. (1994) Temporal changes in the sources of flood basalts: Isotopic and trace element evidence from the 1100 Ma old Keweenawan Mamainse Point Formation, Ontario, Canada. Geochimica et Cosmochimica Acta, 58, 4475—4490.CrossRefGoogle Scholar
Simonetti, A., Goldstein, S.L., Schmidberger, S.S. and Viladkar, S.G. (1998) Geochemical and Nd, Pb, and Sr isotope data from Deccan alkaline complexes – inferences for mantle sources and plume-lithosphere interaction. Journal of Petrology, 39, 1847—1864.CrossRefGoogle Scholar
Steiger, R.H. and Ja¨ger, E. (1977) Subcommision on geochronology: conventions of the use of decay constants in geo- and cosmochronology. Earth and Planetary Science Letters, 36, 359—362.CrossRefGoogle Scholar
Sun, S.S. and McDonough, W.F. (1989) Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. Pp. 313—345 in. Magmatism in Ocean Basins, (Saunders, A.D. and Norry, M.J., editors). Special Publication, 42. Geological Society of London.Google Scholar
Taylor, P.N. and Upton, B.G.J. (1993) Contrasting Pb isotopic compositions in two intrusive complexes of the Gardar Magmatic Province of South Greenland. Chemical Geology, 104, 261—268.CrossRefGoogle Scholar
Taylor, P.N., Jones, N.W. and Moorbath, S. (1984) Isotopic assessment of relative contributions from crust and mantle sources to the magma genesis of Precam brian granit oid rocks. Philosophical Transactions of the Royal Society of London, A310, 605—625.Google Scholar
Taylor, S.R. and McLennan, S.M. (1985) The Continental Crust: its Composition and Evolution. Blackwell Scientific Publications, Oxford, UK.Google Scholar
Thomas, D.N. and Piper, J.D.A. (1992) A revised magnetostratigraphy for the Mid-Proterozoic Garda r lava succ ess ion, Sout h Green land. Tectonophysics, 201, 1—16.CrossRefGoogle Scholar
Turner, S.P., Hawkesworth, C.J., Gallagher, K.G., Stewart, K., Peate, D. and Mantovani, M. (1996) Mantle plumes, flood basalts and thermal models for melt generation beneath continents: assessment of a conductive heating model. Journal of Geophysical Research, 101, 11503—11518.CrossRefGoogle Scholar
Upton, B.G.J. (1996) Anorthosites and troctolites of the Gardar Magmatic Province. Pp. 19—34 in: Petrology and Geochemistry of Magmatic Suites of Rocks in the Continental and Oceanic Crusts (Demaiffe, D., editor). A volume dedicated to Professor Jean Michot, Université Libre de Bruxelles, Royal Museum for Central Africa (Tervuren.Google Scholar
Upton, B.G.J. and Emeleus, C.H. (1987) Mid- Proterozoic alkalin e magmatism in southern Greenland: the Gardar province. Pp. 449—471 in: The Alkaline Rocks (Fitton, J.G. and Upton, B.G.J., editors). Special Publication, 30. Geological Society of London.Google Scholar
Upton, B.G.J., Emeleus, C.H., Heaman, L.M., Goodenough, K.M and Finch, A.A. (2003) Magmatism of the mid-Protero zoic Gardar Province, South Greenland: chronology, petro- genesis and geological setting. Lithos, 68, 43—65.CrossRefGoogle Scholar
Valley, J.W., Kitchen, N., Kohn, M.J., Niendorf, C.R. and Spicuzza, M.J. (1995) UWG-2, a garnet standard for oxygen isotope ratios: strategies for high precision and accura cy with laser heatin g. Geochimica et Cosmochimica Acta, 59, 5223—5231.CrossRefGoogle Scholar
van Breemen, O., Aftalion, M. and Allaart, J.H. (1974) Isotopic and geochronologic studies on granites from the Ketilidian Mobile Belt of South Greenland. Bulletin of the Geological Society of America, 85, 403—412.2.0.CO;2>CrossRefGoogle Scholar
Vroon, P.Z., Lowry, D., Van Bergen, M.J., Boyce, A.J. and Mattey, D.P. (2001) Oxygen isotope systematics of the Banda Arc: Low d18O despite involvement of subducted continental material in magma genesis. Geochimica et Cosmochimica Acta, 65, 589—609.CrossRefGoogle Scholar
Waight, T., Baker, J. and Willigers, B. (2002) Rb isotope dilution analyses by MC-ICPMS using Zr to correct for mass fractionation: towards improved Rb- Sr geochronology. Chemical Geology, 186, 99—116.CrossRefGoogle Scholar
Walsh, J.N., Buckley, F. and Barker, J. (1981) The simultaneous determination of the rare-earth elements in rocks using Inductively Coupled Plasma Source Spectrometry. Chemical Geology, 33, 141—153.CrossRefGoogle Scholar
Weaver, B.L. (1991) The origin of ocean island basalt end-member compositions: trace element and iso- topic constraints. Earth and Planetary Science Letters, 104, 381—397.CrossRefGoogle Scholar
Weaver, B.L., Wood, D.A., Tarney, J. and Joron, J.-L. (1987) Geochemistry of ocean island basalts from the South Atlantic: Ascension, Bouvet, St. Helena, Gough and Tristan da Cunha. Pp. 253—267 in: The Alkaline Rocks (Fitton, J.G. and Upton, B.G.J., editors) . Special Publication, 30. Geological Society of London.Google Scholar
Winchester, J.A. and Floyd, P.A. (1976) Geochemical magma type discrimination; application to altered and metamorphosed basic igneous rocks. Earth and Planetary Science Letters, 28, 459—469.CrossRefGoogle Scholar
Zindler, A. and Hart, S.R. (1986) Chemical geody- namics. Annual Reviews of Earth and Planetary Sciences, 14, 493—571.CrossRefGoogle Scholar

A correction has been issued for this article:

Errata