Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-27T03:11:08.709Z Has data issue: false hasContentIssue false
  • English
  • Français

Evolution of the North Qôroq centre nepheline syenites, South Greenland: alkali-mafic silicates and the role of metasomatism

Published online by Cambridge University Press:  05 July 2018

I. M. Coulson
I. M. Coulson*
Affiliation:
Solid Earth Studies Laboratory, Department of Geology, The University of Regina, Regina, Saskatchewan, Canada, S4S 0A2
*
* E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

The North Qôroq centre comprises a series of concentric nepheline syenite intrusions and forms part of the Igaliko Nepheline Syenite Complex, in the rift-related Gardar Province of South Greenland. The North Qôroq syenites range from mildly undersaturated augite syenite to strongly peralkaline agpaitic nepheline syenite. Extensive in situ fractional crystallization has been postulated for the chemical variation both within units and throughout the centre. Many of the rocks have been affected by metasomatic fluids associated with the emplacement of younger syenite units, and this complicates their interpretation. In this study, the trends and compositions exhibited by pyroxene and amphibole from North Qôroq are examined and related to either primary crystallization or metasomatic activity (e.g. controls of fO2, peralkalinity). Implications thus drawn are used to interpret the chemical processes inherent in the chemical and fluid evolution of alkaline magmas, and, in particular, the transition from miaskitic to agpaitic magmatism. In general, the major phases of the North Qôroq syenites records the increasing evolution of the units by crystal fractionation, towards peralkaline compositions. The composition of olivine, in the least evolved syenites, also points to a relatively high state of fractionation of the parent magma, whilst pyroxene and amphibole record an overall decrease in Mg/Mg+Fe), and a general increase in Fe3+ and alkali content, with increased fractionation. The increasing peralkalinity of the magma also governs the evolution of pyroxene and, to a lesser degree, amphibole towards higher Zr and Ti contents in the more Na-rich compositions. The trends for pyroxene from metasomatized syenite show similar patterns, but lower Fe2+ enrichment, suggesting the source of the metasomatic fluids is similar to the evolving syenites. The presence of amphiboles in metasomatic rocks, and high F contents attest to the F-rich nature of the metasomatic fluids, which is in agreement with results previously reported for metasomatic fluorapatite.

Keywords

nepheline syenite rocksalkali-mafic silicatesmetasomatismGardar ProvinceGreenland.
Type
Research Article
Information
Mineralogical Magazine , Volume 67 , Issue 5 , October 2003 , pp. 873 - 892
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

Anderson, J.G. (1974) The Geology of Ala´ngorssuaq, northern Nunarssuit complex, South Greenland. PhD thesis, University of Aberdeen, UK.Google Scholar
Aoki, K. (1964) Clinopyroxenes from alkaline rocks of Japan. American Mineralogist, 49, 1199—1223.Google Scholar
Arzamastsev, A.A., Belyatsky, B.V. and Arzamastseva, L.V. (2000) Agpaitic magmatism in the northeastern Baltic Shield: a study of the Niva intrusion, Kola Peninsula, Russia. Lithos, 51, 27—46.CrossRefGoogle Scholar
Bailey, D.K. (1969) The stability of acmite in the presence of H2O. American Journal of Science, 267A, 1—16.Google Scholar
Blaxland, A.B., van Breemen, O., Emeleus, C.H. and Anderson, J.G. (1978) Age and origin of the major syenite centres in the Gardar province of South Greenland: Rb-Sr studies. Bulletin of the Geological Society of America, 89, 231—244.2.0.CO;2>CrossRefGoogle Scholar
Brooks, C.R. and Gill, R.C.O. (1982) Compositional variations in the pyroxenes and amphiboles of the Kangerdlugssuaq intrusion, East Greenland: further evidence for the crustal contamination of syenite magma. Mineralogical Magazine, 45, 1—9.CrossRefGoogle Scholar
Chambers, A.D. (1976) The Petrology and Geochemistry of the North Qôroq Centre, Igaliko Complex, South Greenland. PhD thesis, University of Durham, UK.Google Scholar
Coulson, I.M. (1996) Rare-earth and High-Field- Strength Element Mobility in and around the North Qôroq Centre, Gardar Province of South Greenland. PhD thesis, University of Birmingham, UK.Google Scholar
Coulson, I.M. (1997) Post-magmatic alteration in eudialyte from the North Qôroq centre, South Greenland. Mineralogical Magazine, 61, 99—109.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—78.Google Scholar
Coulson, I.M., Leng, M.J., Pearce, N.J.G. and Chambers, A.D. (1998) The origin of carbonatites in the North Qôroq central complex, and possible links with carbonatite/ alkaline magmatism in the Precambrian Gardar rift of Southern Greenland. Volcanic and Magmatic Studies Group annual meeting, Leicester, UK. Program with abstracts, p. 16.Google Scholar
Coulson, I.M., Goodenough, K.M., Pearce, N.J.G. and Leng, M.J. (2003) Carbonatites and lamprophyres of the Gardar Province – a ‘window’ to the sub-Gardar mantle. Mineralogical Magazine, 67, 855—872.CrossRefGoogle Scholar
Deer, W.A., Howie, R.A. and Zussman, J. (1992) An Introduction to the Rock-forming Minerals (2nd edition). Longman Scientific & Technical, Harlow, Essex, UK.Google Scholar
Deer, W.A., Howie, R.A. and Zussman, J. (1997) Rockforming Minerals - Volume 2B Double-chain Silicates (2nd edition). The Geological Society, London, UK.Google Scholar
Droop, G.T.R. (1987) A general equation for estimating Fe3+ concentrations in ferromagnesian silicates and oxides from microprobe analyses, using stoichiometric criteria. Mineralogical Magazine, 51, 431—435.CrossRefGoogle Scholar
Duggan, M.B. (1988) Zirconium-rich sodic pyroxenes in felsic volcanics from the Warrumbungle Volcano, New South Wales, Australia. Mineralogical Magazine, 52, 491—496.CrossRefGoogle Scholar
Emeleus, C.H. and Harry, W.T. (1970) The Igaliko Nepheline syenite complex: general description. Meddelelser om Grønland, 186, 3, 115.pp.Google 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). The Geological Survey of Greenland (GGU), Copenhagen, Denmark.Google Scholar
Ernst, W.G. (1962) Synthesis, stability relations, and occurrence of riebeckite and riebeckite-arfvedsonite solid solutions. Journal of Geology, 70, 689—736.CrossRefGoogle Scholar
Finch, A.A. (1991) Conversion of nepheline to sodalite during subsolidus processes in alkaline rocks. Mineralogical Magazine, 55, 459—63.CrossRefGoogle Scholar
Finch, A.A., Goodenough, K.M., Salmon, H.M. and Andersen, T. (2001) The petrology and petrogenesis of the North Motzfeldt Centre, Gardar Province, South Greenland. Mineralogical Magazine, 65, 759—74.CrossRefGoogle Scholar
Gaeta, M. and Freda, C. (2001) Strontian fluoromagnesiohastingsite in Alban Hills lavas (Central Italy): constraints on crystallization conditions. Mineralogical Magazine, 65, 787—795.CrossRefGoogle Scholar
Garde, A.A., Chadwick, B., Grocott, J., Hamilton, M., McCaffrey, K. and Swager, C.P. (1998) An overview of the Palaeoproterozoic Ketilidian Orogen, South Greenland. In: Lithopro be Eastern Canadia n Onshore-Offshore Transect (ESCOOT): report of 1998 transect meeting. Compiled by Wardle, R.J. and Hall, J.. Lithoprobe Report, 68, 50—66.Google 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, magmat ism, and fore -ar c accr etion during Palaeoproterozoic oblique convergence. Canadian Journal of Earth Sciences, 39, 765—93.CrossRefGoogle Scholar
Giret, A., Bonin, B. and Leger, J.M. (1980) Amphibole compositional trends in oversaturated and undersaturated alkaline plutonic ring-complexes. The Canadian Mineralogist, 18, 481—95.Google Scholar
Grapes, R., Yagi, K. and Okumura, K. (1979) Aenigmatite, sodic pyroxene, arfvedsonite and associa ted minerals from Morutu, Sakhalin. Contributions to Mineralogy and Petrology, 69, 97—103.CrossRefGoogle Scholar
Jones, A.P. (1980) The Petrology and Structure of the Motzfeldt Centre, Igaliko, South Greenland. PhD thesis, University of Durham, UK.Google Scholar
Jones, A.P. (1984) mafic silicates from the nepheline syenites of the Motzfeldt centre, South Greenland. Mineralogical Magazine, 48, 1—12.CrossRefGoogle Scholar
Jones, A.P. and Peckett, A. (1980) Zirconium-bearing aegirines from Motzfe ldt, South Greenlan d. Contributions to Mineralogy and Petrology, 75, 251—255.CrossRefGoogle Scholar
Larsen, L.M. (1976) Clinopyroxenes and coexisting mafic minerals from the alkaline Ilõ´maussaq intrusion, South Greenland. Journal of Petrology, 17, 258—290.CrossRefGoogle Scholar
Leake, B.E. (1965) The relationship between tetrahedral aluminum and the maximum possible octahedral aluminum in natural calciferous and subcalciferous amphiboles. American Mineralogist, 50, 843—851.Google Scholar
Leake, B.E. and 21 others (1997) Nomenclature of the amphiboles: report of the sub-committee on amphiboles of the International Mineralogical Association, Commission on New Minerals and Mineral Names. Mineralogical Magazine, 61, 295—321.CrossRefGoogle Scholar
MacDonald, R. and Upton, B.G.J. (1993) The Proterozoic Gardar rift zone, south Greenland: comparisons with the East African Rift System. Pp. 427—42 in: Magmatic Processes and Plate Tectonics (H.M. Prichard, T. Alabaster, N.B.W. Harris and Neary, C.R., editors). Special Publication, 76. The Geological Society, London.Google Scholar
Markl, G., Marks, M., Schwinn, G. and Sommer, H. (2001) Phase equilibrium constraints on intensive crystal lisation parameters of the Ilõ´maussaq Complex, South Greenland. Journal of Petrology, 42, 2231—2258.CrossRefGoogle Scholar
Marks, M. and Markl, G. (2001) Fractionation and assimilation processes in the alkaline augite syenite unit of the Ilõ´maussaq intrusion, South Greenland, as deduced from phase equilibria. Journal of Petrology, 42, 1947—1969.CrossRefGoogle Scholar
Mitchell, R.H. (1990) A review of the compositional variation of amphiboles in alkaline plutonic complexes. Lithos, 26, 135—56.CrossRefGoogle Scholar
Mitchell, R.H. and Platt, R.G. (1978) mafic mineralogy of ferroaugite syenite from the Coldwell alkaline complex, Ontario, Canada. Journal of Petrology, 19, 627—651.CrossRefGoogle Scholar
Morimoto, N. and Subcommittee on Pyroxenes (1989) Nomencl ature of Pyroxenes. The Canadia n Mineralogist, 27, 143—156.Google Scholar
Nash, W.P. and Wilkinson J.F.G. (1970) Shonkin Sag laccolith, Montana. I: mafic minerals and estimates of temperature, pressure, oxygen fugacity and silica activity. Contributions to Mineralogy and Petrology, 25, 241—269.CrossRefGoogle Scholar
Nielsen, T.F.D. (1979) The occurrence and formation of Ti-aegirines in peralkaline syenites. Contributions to Mineralogy and Petrology, 69, 235—244.CrossRefGoogle Scholar
Parsons, I., Mason, R.A., Becker, S.M. and Finch, A.A. (1991) Biotite equilibria and fluid circulation in the Klokken intrusion. Journal of Petrology, 32, 1299—1333.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. Geological Society of America Bulletin, 105, 272—278.2.3.CO;2>CrossRefGoogle Scholar
Pearce, N.J.G. (1989) Zirconium-bearing amphibole from the Igaliko Dyke Swarm, South Greenland. Mineralogical Magazine, 53, 107—110.CrossRefGoogle Scholar
Piilonen, P.C., McDonald, A.M. and Lalonde, A.E. (1998) The crystal chemistry of aegirine from Mont Saint-Hilaire, Quebec. The Canadian Mineralogist, 36, 779—791.Google Scholar
Platt, R.G. and Woolley, A.R. (1986) The mafic mineralogy of peralkaline syenites and granites of the Mulanje Complex, Malawi. Mineralogical Magazine, 50, 85—99.CrossRefGoogle Scholar
Powell, B.M. (1978) The crystallisation history of the Igdle r. gss alik nephe line syeni te int rusi on, Greenland. Lithos, 11, 99—120.CrossRefGoogle Scholar
Preston, R.J., Hole, M.J., Bouch, J. and Still, J. (1998) The occurrence of zirconian aegirine and calcic catapleiite (CaZrSi3O9.2H2O) within a nepheline syenite, British Tertiary Igneous Province. Scottish Journal of Geology, 34, 173—180.CrossRefGoogle Scholar
Preston, R.J., Hole, M.J. and Still, J. (2000) The occurrence of Zr-bearing amphiboles and their relationships with the pyroxenes and biotites in the teschenite and nepheline syenites of a differentiated dolerite boss, Islay, NW Scotland. Mineralogical Magazine, 64, 459—468.CrossRefGoogle Scholar
Rae, D.A. (1988) Metasomatism associated with the North Qôroq Centre, South Greenland. PhD thesis, University of Aston in Birmingham, UK.Google Scholar
Rae, D.A. and Chambers, A.D. (1988) Metasomatism in the North Qô roq centre , South Greenla nd: Cathodoluminescence and mineral chemistry of alkali feldspars. Transactions of the Royal Society of Edinburgh: Earth Sciences, 79, 1—12.CrossRefGoogle Scholar
Rae, D.A., Coulson, I.M. and Chambers, A.D. (1996) Metasomatism in the North Qôroq centre, South Greenland: apatite chemistry and rare-earth element transport. Mineralogical Magazine, 60, 207—220.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
Rowbotham, G. and Farmer, V.C. (1973) The effect of "A" site occupancy upon the hydroxyl stretching frequency in clinoamphiboles. Contributions to Mineralogy and Petrology, 38, 147—149.CrossRefGoogle Scholar
Schumacher, J.C. (1997) The estimation of ferric iron in electron microprobe analysis of amphibol es. Mineralogical Magazine, 61, 312—321.Google Scholar
Shearer, C.K. and Larsen, L.M. (1994) Sector-zoned aegirine from the Ilõ´muassaq alkaline intrusion, South Greenland: implications for trace-element behaviour in pyroxene. American Mineralogist, 79, 340—352.Google Scholar
Stephenson, D. (1972) Alkali clinopyroxenes from nepheline syenites of the South Qôroq Centre, South Greenland. Lithos, 5, 187—201.CrossRefGoogle Scholar
Stephenson, D. and Upton, B.G.J. (1982) Ferromagnesian silicates in a differentiated alkaline complex: Kuˆ ngnaˆ t Fjeld, South Greenland. Mineralogical Magazine, 46, 283—300.CrossRefGoogle Scholar
Strong, D.F. and Taylor, R.P. (1984) Magmaticsubsolidus and oxidation trends in composition of amphiboles from silica-saturated peralkaline igneous rocks. Tschermaks Mineralogie und Petrographie Mitteilungen, 32, 211—222.CrossRefGoogle Scholar
Upton, B.G.J. (1974) The alkaline province of Southwest Greenland. Pp. 221—38 in: The Alkaline Rocks (Sørensen, H., editor). John Wiley & Sons, Chichester, UK.Google Scholar
Upton, B.G.J. and Emeleus, C.H. (1987) Mid Proterozo ic alkalin e magmatism is southern Greenland. Pp. 449—471 in: Alkaline Igneous Rocks (Fitton, J.G. and Upton, B.G.J., editors). Special Publication, 30. The Geological Society, London.Google Scholar
Upton, B.G.J., Emeleus, C.H., Heaman, L.M., Goodenough, K.M. and Finch, A.A. (2003) Magmat ism of the mid-Protero zoic Gardar Province, South Greenland: chronology, petrogenesis and geological setting. Lithos, 68, 43—65.CrossRefGoogle Scholar
Woolley, A.R. and Platt, R.G. (1988) The peralkaline nepheline syenites of the Junguni intrusion, Chilwa province, Malawi. Mineralogical Magazine, 52, 425—433.CrossRefGoogle Scholar
Yagi, K. (1966) The system acmite-diopside and its bearing on the stability relationships of natural pyroxenes of the acmite-diposide series. American Mineralogist, 51, 976—1000.Google Scholar