Hostname: page-component-cd9895bd7-jkksz Total loading time: 0 Render date: 2024-12-19T15:25:57.300Z Has data issue: false hasContentIssue false
  • English
  • Français

Petrochemistry of late Palaeozoic alkali lamprophyre dykes from N Scotland

Published online by Cambridge University Press:  03 November 2011

A. N. Baxter
A. N. Baxter
Affiliation:
Department of Geology, City of London Polytechnic, Bigland Street, London E1 2NG, U.K.
Get access Rights & Permissions [Opens in a new window]

Abstract

The lower Carboniferous–late Permian dyke swarms of the Scottish Highlands and Islands comprise a mild-strongly alkaline basic series of dolerites, camptonites and monchiquites. Differentiation within the suite was largely controlled by olivine + clinopyroxene fractionation. Major and trace element data indicate that dolerites and camptonites chemically overlap, their mineralogical contrasts resulting from differential loss of an H2O, CO2-rich fluid phase during ascent. By contrast most monchiquites have high Mg-values and are relatively primitive compositions, some being near-primary magmas which have risen rapidly from mantle levels with little chemical modification.

HREE-buffered incompatible element profiles imply a garnet–lherzolite source, which must underlie the lithospheric mantle region represented by spinel lherzolite xenoliths found in some monchiquites. C. 0·5–2·0% partial melting can account for the gross incompatible element variation in the suite, but relative fluctuations in K, Ba, Rb, Sr, P and Zr imply chemical heterogeneity controlled either by refractory mantle accessory phases or by modification of magmas during ascent through variably metasomatised lithospheric mantle.

Keywords

Camptonitecontinental intra-plate basaltic volcanismincompatible element enrichmentmantle processesmonchiquite
Type
Research Article
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 77 , Issue 4 , 1987 , pp. 267 - 277
Copyright
Copyright © Royal Society of Edinburgh 1987

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

Allègre, C. J. 1982. Chemical Geodynamics. TECTONOPHYSICS 81, 109–32.CrossRefGoogle Scholar
Allègre, C. J., Dupŕe, B., Lambret, B. & Richard, P. 1981. The sub-continental versus sub-oceanic debate, 1. Lead-Neodymium-Strontium isotopes in primary alkali basalts from a shield area: Ahaggar volcanic suite. EARTH PLANET SCI LETT 52, 85–92.CrossRefGoogle Scholar
Bailey, D. K. 1982. Mantle metasomatism—continuing chemical change within the Earth. NATURE 296, 525–30.CrossRefGoogle Scholar
Baxter, A. N. 1976. Geochemistry and petrogenesis of primitive alkali basalt from Mauritius, Indian Ocean. BULL GEOL SOC AM 87, 1028–34.2.0.CO;2>CrossRefGoogle Scholar
Baxter, A. N. 1978. Ultramafic and mafic nodule suites in shield-forming lavas from Mauritius. J GEOL SOC LONDON 140, 105–22.Google Scholar
Baxter, A. N. & Mitchell, J. G. 1984. Camptonite–Monchiquite dyke swarms of Northern Scotland; Age relationships and their implications. SCOTT J GEOL 20, 297–308.CrossRefGoogle Scholar
Boettcher, A. L., O'Neil, J. R., Windom, K. E., Stewart, D. C. & Wilshire, H. G. 1979. Metasomatism of the upper mantle and the genesis of kimberlites and alkali basalts. In Boyd, F. R. & Meyer, D. A. (eds) The Mantle Sample: Inclusions in Kimberlites and other Volcanics. Proc 2nd Int. Kimberlite Conference 2, 173–80.CrossRefGoogle Scholar
Brooks, C. K. 1976. The Fe2O3/FeO ratio of basalt analyses: an appeal for a standardized procedure. BULL GEOL SOC DENMARK 25, 117–20.CrossRefGoogle Scholar
Chapman, N. A. 1974. Petrology of inclusions from some late Palaeozoic British volcanic rocks. Unpublished PhD. Thesis, Edinburgh University.Google Scholar
Clague, D. A. & Frey, F. A. 1982. Petrology and trace element geochemistry of the Honolulu volcanics, Oahu: implications for the oceanic mantle below Hawaii. J PETROL 23, 447–50.CrossRefGoogle Scholar
Cooper, A. F. 1979. Petrology of ocellar lamprophyres from western Otago, New Zealand. J PETROL 20, 139–64.CrossRefGoogle Scholar
De Laeter, J. R. & Hosie, D. J. 1978. The abundance of barium in stony meteorites. EARTH PLANET SCI LETT 38, 416–20.CrossRefGoogle Scholar
De Souza, H. A. F. 1982. Age data from Scotland and the Carboniferous time scale. In Odin, G. S. (ed.) Numerical dating in stratigraphy. Pt. 1, 455–66 Chichester: John Wiley.Google Scholar
Fitton, J. G. & Dunlop, H. M. 1985. The Cameroon line, West Africa, and its bearing on the origin of oceanic and continental alkali basalt. EARTH PLANET SCI LETT 72, 23–8.CrossRefGoogle Scholar
Francis, E. H. 1978a. The Midland Valley as a rift, seen in connection with the late Palaeozoic European rift system. In Ramberg, I. B. & Neumann, E.-R. (eds) Tectonics and geophysics of continental rifts, 133–48. Dordrecht: D. Reidel.CrossRefGoogle Scholar
Francis, E. H. 1978b. Igneous activity in a fractured craton: Carboniferous volcanism in northern Britain. In Bowes, D. R. & Leake, B. E. (eds) Crustal evolution in northwest Britain and adjacent areas. GEOL J SPEC ISSUE 10, 279–96.Google Scholar
Francis, E. H. 1983a. Carboniferous. In Craig, G. Y. (ed.) Geology of Scotland (2nd edition), 253–96. Edinburgh: Scottish Academic Press.Google Scholar
Francis, E. H. 1983b. Carboniferous—Permian Igneous Rocks. In Craig, G. Y. (ed.) Geology of Scotland (2nd edition), 297–324. Edinburgh: Scottish Academic Press.Google Scholar
Frey, F. A., Green, D. H. & Roy, S. D. 1978. Integrated models of basalt petrogenesis: a study of quartz tholeiites to olivine melilitites from south-eastern Australia utilising geochemical and experimental petrological data. J PETROL 19, 463–513.CrossRefGoogle Scholar
Gibb, F. G. F. 1973. The zoned clinopyroxenes of the Shiant Isles sill, Scotland. J PETROL 14, 203–30.CrossRefGoogle Scholar
Hartley, J. & Leedal, G. P. 1951. A monchiquite vent, Stob a Ghrianain, Inverness-shire. GEOL MAG 88, 140–4.CrossRefGoogle Scholar
Hoffman, A. W. 1979. Isotope and trace element geochemistry of the Earth's mantle. In Jäger, E. & Hunziker, J. C. (eds) Lectures in Isotope Geology, 203–6. Berlin: Springer-Verlag.CrossRefGoogle Scholar
Hoffman, A. W. & White, W. M. 1982. Mantle plumes from ancient oceanic crust. EARTH PLANET SCI LETT 57, 421–36.CrossRefGoogle Scholar
Leake, B. E. 1978. The nomenclature of amphiboles. MINER MAG 42, 533–63.CrossRefGoogle Scholar
Le Maitre, R. W. 1976. Some problems of the projection of chemical data into mineralogical classifications. CONTRIB MINERAL PETROL 56, 181–9.CrossRefGoogle Scholar
Macdonald, R. 1975. Petrochemistry of the early Carboniferous (Dinantian) lavas of Scotland. SCOTT J GEOL 11, 269–314.CrossRefGoogle Scholar
Macdonald, R. 1980. Trace element evidence for mantle heterogeneity beneath the Scottish Midland Valley in the Carboniferous and Permian. PHILOS TRANS R SOC LONDON A297, 245–57.Google Scholar
Macdonald, R., Thomas, J. E. & Rizzelo, S. A. 1977. Variations in basalt chemistry with time in the Midland Valley province during the Carboniferous and Permian. SCOTT J GEOL 13, 11–22.CrossRefGoogle Scholar
MacDonald, J. G. & Whyte, F. 1981. Petrochemical evidence for the genesis of a Lower Carboniferous transitional basaltic suite in the Midland Valley of Scotland. TRANS R SOC EDINBURGH: EARTH SCI 72, 75–88.CrossRefGoogle Scholar
MacGregor, A. G. 1948. Problems of Carboniferous—Permian volcanicity in Scotland. J GEOL SOC LONDON 104, 133–52.CrossRefGoogle Scholar
McKenzie, D. & O'Nions, P. J. 1983. Mantle reservoirs and ocean island basalts. NATURE 301, 229–301.CrossRefGoogle Scholar
McLean, A. C. 1978. Evolution of fault-controlled ensialic basins. In Bowes, D. R. & Leake, B. E. (eds) Crustal evolution in northwestern Britain. GEOL J SPEC ISSUE 10, 325–46.Google Scholar
Mason, B. 1979. in Data of Geochemistry. Chapter B: Cosmochemistry. Part 1: Meteorites. PROF PAP US GEOL SURV, 1–132.Google Scholar
Nakamura, N. 1974. Determination of REE, Ba, Fe, Mg, Na and K in carbonaceous and ordinary chondrites. GEOCHIM COSMOCHIM ACTA 38, 757–75.CrossRefGoogle Scholar
Odin, G. S. & Letolle, R. 1982. The Triassic time scale in 1981. In Odin, G. S. (ed.) Numerical dating in stratigraphy Part 1, 523–36. Chichester: John Wiley.Google Scholar
Phillips, W. E. A., Stillman, C. J. & Murphy, T. 1976. A Caledonian plate tectonic model. J GEOL SOC LONDON 132, 579–609.CrossRefGoogle Scholar
Price, W. J. 1979. Spectrochemical analysis by atomic absorption. London: Heyden.Google Scholar
Rock, N. M. S. 1983. The Permo—Carboniferous camptonite—monchiquite dyke-suite of the Scottish Highlands and Islands: Field, distribution and petrological aspects. REP INST GEOL SCI 82/14.Google Scholar
Rock, N. M. S. 1986. The nature and origin of ultramafic lamprophyres: Alnoites and allied rocks. J PETROL 27, 155–196.CrossRefGoogle Scholar
Shima, M. 1979. The abundances of titanium, zirconium and hafnium in stony meteorites. GEOCHIM COSMOCHIM ACTA 43, 353–62.CrossRefGoogle Scholar
Smedley, P. L. 1986. The relationship between calc-alkaline volcanism and within-plate volcanism: evidence from Scottish Palaeozoic lavas. EARTH PLANET SCI LETT 76, 113–28.CrossRefGoogle Scholar
Speight, J. M. & Mitchell, J. G. 1979. The Permo—Carboniferous dyke swarm of northern Argyll and its bearing on the dextral displacement on the Great Glen Fault. J GEOL SOC LONDON 136, 3–11.CrossRefGoogle Scholar
Streckeisen, A. 1979. IUGS Subcommission on the systematics of igneous rocks: classification and nomenclature of volcanic rocks, lamprophyres, carbonatites and melilitic rocks. NENES JAHRB MIN ABH 134, 1–14.Google Scholar
Sun, S. S. 1980. Lead isotope study of young volcanic rocks from mid-ocean ridges, ocean islands and island arcs. PHILOS TRANS R SOC LONDON A297, 409–45.Google Scholar
Sun, S. S. & Hanson, G. N. 1975. Origins of Ross Island basanitoids and limitations upon the heterogeneity of mantle sources for alkali basalts and nephelinites. CONTRIB MINERAL PETROL 52, 77–106.CrossRefGoogle Scholar
Thirlwall, M. F. 1981. Implications for Caledonian plate tectonic models of chemical data from volcanic rocks of the British Old Red Sandstone. J GEOL SOC LONDON 138, 123–38.CrossRefGoogle Scholar
Thompson, R. N. 1982. Magmatism of the British Tertiary volcanic province (Carnegie Review Article). SCOTT J GEOL 18, 49–107.CrossRefGoogle Scholar
Thompson, M. & Walsh, J. N. 1983. A handbook of inductively coupled plasma emission spectrometry. London: Blackie.Google Scholar
Upton, B. G. J. 1982. Carboniferous to Permian volcanism in the stable foreland. In Sutherland, D. S. (ed.) Igneous rocks of the British Isles, 255–75. Chichester: John Wiley.Google Scholar
Upton, B. G. J., Aspen, P., & Chapman, N. A. 1983. The upper mantle and deep crust beneath the British Isles: evidence from inclusions in volcanic rocks. J GEOL SOC LONDON 140, 105–22.CrossRefGoogle Scholar
Upton, B. G. J., Fitton, J. G. & Macintyre, R. M. 1987. The Glas Eilean lavas: Evidence of a Lower Permian volcano—tectonic basin between Islay and Jura, Inner Hebrides. TRANS R SOC EDINBURGH: EARTH SCI 77, 289–93.CrossRefGoogle Scholar
Walsh, J. N., Buckley, F. & Barker, J. 1981. The simultaneous determination of the rare earth elements in rocks using inductively coupled plasma source spectrometry. CHEM GEOL 33, 141–53.CrossRefGoogle Scholar
Watson, E. B. 1982. Melt infiltration and magma evolution. GEOLOGY 10, 236–40.2.0.CO;2>CrossRefGoogle Scholar
Watson, J. V. 1984. The ending of the Caledonian orogeny in Scotland. J GEOL SOC LONDON 141, 193–214.CrossRefGoogle Scholar
Zeigler, P. A. 1975a. North Sea basin history in the tectonic framework of northwestern Europe. In Woodland, A. D. (ed.) Petroleum and the continental shelf of NW Europe, 131–49. Amsterdam: Applied Science Publ.Google Scholar
Zeigler, P. A. 1975b. Outline of the geological history of the North Sea. In Woodland, A. D. (ed.) Petroleum and the continental shelf of NW Europe, 165–90. Amsterdam: Applied Science Publ.Google Scholar
Zeigler, P. A. 1978. North Sea rift and basin development. In Ramberg, I. B. & Neumann, E.-R. (eds) Tectonics and geophysics of continental rifts, 249–77. Dordrecht: D. Reidel.CrossRefGoogle Scholar