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Age constraints on basement of the Midland Valley of Scotland

Published online by Cambridge University Press:  03 November 2011

M. Aftalion ,
O. van Breemen  and
D. R. Bowes
M. Aftalion
Affiliation:
Isotope Geology Unit, Scottish Universities Research and Reactor Centre, East Kilbride, Glasgow G75 0QU, Scotland.
O. van Breemen
Affiliation:
Geological Survey of Canada, 601 Booth Street, Ottawa, Canada K1A0E8.
D. R. Bowes
Affiliation:
Department of Geology, University of Glasgow, Glasgow G12 8QQ, Scotland.
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Abstract

The existence of a basement of granulite beneath the Midland Valley is supported by investigations of inclusions in volcanic rocks and the geophysical studies of the LISPB experiment. To establish age constraints for this basement, a compilation is presented of available Rb–Sr whole-rock, common lead, U–Pb zircon and Sm–Nd radiometrie data for crystalline rocks in Scotland from the earliest recognised crust (c. 2900 Ma) to 380 Ma (“end” of Caledonian orogeny) including xenoliths in volcanic vents and boulders in conglomerates.

For rocks within the Midland Valley, isotopic data provide four lines of evidence. (1) An upper intercept U–Pb age of c. 1700 Ma for detrital zircons from a lower Palaeozoic greywacke from Dalmellington corresponds to a late stage of the Laxfordian orogenic episode (early Proterozoic) with possibly some overprinting during the Grenvillian episode (mid Proterozoic). (2) The common lead composition of the Distinkhorn granite suggests the participation of early Proterozoic basement during granite emplacement. (3) For xenoliths from the Carboniferous Partan Craig vent, one gives a Sm–Nd CHUR model age of 1180 ± 55 Ma, a second yielded a Sm–Nd garnet—potassium feldspar age of 356 ± 6 Ma and an upper intercept U–Pb age from zircons from the third is c. 2200 (± 240) Ma; for xenoliths from other vents, an Rb–Sr whole-rock isochron of 1101 ± 63 Ma and an Sm–Nd model age of c. 1100 Ma arerecorded. (4) A linear array corresponding to an apparent age of 770 ± 180 Ma on a Pb–Pb isochron diagram for Tertiary igneous rocks of Arran points to an underlying basement of late Precambrian orthogneiss.

The existence of basement made of products of the Grenvillian episode, or predominantly so, similar to the basement N of the Highland Boundary fault, is not inconsistent with the available evidence. However, zircons and other rock components appear to have an ultimate Lewisian provenance. At least in parts, there is also a strong late Proterozoic imprint. Further studies are required for an unequivocal solution.

Keywords

CaledonianconcordiagranuliteGrenvillianInverianKnoydartianLaxfordianPb–PbRb–SrScourianSm–NdU–Pbupper interceptzircon
Type
Regional framework
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 75 , Issue 2: Deep Geology of the Midland Valley of Scotland and Adjacent Regions. Bicentenary Symposium , 1984 , pp. 53 - 64
Copyright
Copyright © Royal Society of Edinburgh 1984

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References

Aftalion, M. & van Breemen, O. 1980. U–Pb zircon, monazite and Rb–Sr whole rock systematics of granitic gneiss and psammitic to semipeli tic host gneiss from Glenfinnan, north-western Scotland. CONTRIB MINERAL PETROL 72, 87–98.CrossRefGoogle Scholar
Allègre, C. J., Albarè, F., Grünenfelder, M. & Köppel, V. 1974. 238U/206Pb—235U/207Pb—232Th/208Pb zircon geochronology in Alpine and non-Alpine environment. CONTRIB MINERAL PETROL 43, 163–94.CrossRefGoogle Scholar
Bamford, D., Nunn, K., Prodehl, C. & Jacob, B. 1977. LISPB-III Upper crustal structure of northern Britain. J GEOL SOC LONDON 133, 481–8.CrossRefGoogle Scholar
Bell, K. 1968. Age relations and provenance of the Dalradian Series of Scotland. BULL GEOL SOC AM 79, 1167–94.CrossRefGoogle Scholar
Bikerman, M., Bowes, D. R. & van Breemen, O. 1975. Rb–Sr whole rock isotopie studies of Lewisian metasediments and gneisses in the Loch Maree region, Ross-shire. J GEOL SOC LONDON 131, 237–54.CrossRefGoogle Scholar
Blaxland, B. J., Aftalion, M. & van Breemen, O. 1979. Pb isotopie composition of feldspars from Scottish Caledonian granites, and the nature of the underlying crust. SCOTT J GEOL 15, 130–51.CrossRefGoogle Scholar
Bluck, B. J. 1984. Pre-Carboniferous history of the Midland Valley of Scotland. TRANS R SOC EDINBURGH EARTH SCI 75, 275–95.CrossRefGoogle Scholar
Bluck, B. J., Halliday, A. N., Aftalion, M. & Macintyre, R. M. 1980. Age and origin of the Caledonian orogeny and the Ordovician time scale. GEOLOGY 8, 492–5.2.0.CO;2>CrossRefGoogle Scholar
Bowes, D. R. 1978. Shield formation in Precambrian times: the Lewisian complex. In Bowes, D. R. & Leake, B. E. (eds) Crustal evolution in northwestern Britain and adjacent regions, 39–80. GEOL J SPEC ISSUE 10.Google Scholar
Bowes, D. R. 1980. The absolute time-scale and the subdivision of Precambrian rocks in northwestern Britain. In Mitrofanov, F. P. (ed.) Principles and criteria of subdivision of Precambrian in mobile zones, 32–54. Leningrad: Nauka.Google Scholar
Bowes, D. R. & Gaál, G. 1981. Precambrian record of the eastern North Atlantic Borderlands. In Kerr, J. W. & Fergusson, A. J. (eds) Geology of the North Atlantic Borderlands, 31–55. MEM CAN SOC PET GEOL 7.Google Scholar
Bowes, D. R., Hopgood, A. M. & Pidgeon, R. T. 1976. Source ages of zircons in an Archaean quartzite, Rona, Inner Hebrides, Scotland. GEOL MAG 113, 545–52.CrossRefGoogle Scholar
Brook, M., Brewer, M. S. & Powell, D. 1976. Grenville age for rocks in the Moine of north-western Scotland. NATURE 260, 515–7.CrossRefGoogle Scholar
Brook, M., Powell, D. & Brewer, M. S. 1977. Grenville events in the Moine rocks of the Northern Highlands, Scotland. J GEOL SOC LONDON 133, 489–96.CrossRefGoogle Scholar
Chapman, H. J. 1979. 2390 Myr Rb–Sr whole-rock for the Scourie dykes of north-west Scotland. NATURE 277, 642–3.CrossRefGoogle Scholar
Chapman, H. J. & Moorbath, S. 1977. Lead isotope measurements from the oldest recognised Lewisian gneisses of north-west Scotland. NATURE 268, 41–2.CrossRefGoogle Scholar
Clayburn, J. A. P., Harmon, R. S., Pankhurst, R. J. & Brown, J. F. 1983. Sr, O and Pb-isotope evidence for origin and evolution of Etive Igneous Complex, Scotland. NATURE 303, 492–7.CrossRefGoogle Scholar
Cliff, R. A., Gray, C. M. & Huhma, H. 1983. A Sm–Nd isotopie study of the South Harris Igneous Complex, the Outer Hebrides. CONTRIB MINERAL PETROL 82, 91–8.CrossRefGoogle Scholar
Davies, G. R., Upton, B. G. J. & Strogen, P. 1984. Sr and Nd isotope evidence for age and origin of crustal xenoliths from the Midland Valley of Scotland and central Ireland (Abstract), TRANS R SOC EDINBURGH EARTH SCI 75, 297.Google Scholar
Dewey, J. F. & Pankhurst, R. J. 1970. The evolution of the Scottish Caledonides in relation to their isotopie age pattern. TRANS R SOC EDINBURGH 68, 361–89.CrossRefGoogle Scholar
Dickin, A. P. 1981. Isotope geochemistry of Tertiary igneous rocks from the Isle of Skye, N.W. Scotland. J PETROL 22, 155–89.CrossRefGoogle Scholar
Dickin, A. P. & Jones, N. W. 1983. Isotopie evidence for the age and origin of pitchstones and felsites, Isle of Eigg, N.W. Scotland. J GEOL SOC LONDON 140, 691–700.CrossRefGoogle Scholar
Dickin, A. P., Moorbath, S. & Welke, H. J. 1981. Isotope, trace element and major element geochemistry of Tertiary igneous rocks, Isle of Arran, Scotland. TRANS R SOC EDINBURGH EARTH SCI 72, 159–70.CrossRefGoogle Scholar
Doe, B. R. & Zartman, R. E. 1980. Plumbotectonics, the Phanerozoic. In Barnes, H. L. (ed.) Geochemistry of hydrothermal ore deposits, 2nd edn, 22–70. New York: Wiley-Interscience.Google Scholar
Evans, C. R. & Tarney, J. 1964. Isotopie ages of Assynt dykes. NATURE 207, 54–6.CrossRefGoogle Scholar
Francis, P. W., Moorbath, S. & Welke, H. J. 1971. Isotopie age data for Scourian intrusive rocks on the Isle of Barra, Outer Hebrides, northwest Scotland. GEOL MAG 108, 13–22.CrossRefGoogle Scholar
Graham, A. M. & Upton, B. J. G. 1978. Gneisses in diatremes, Scottish Midland Valley: petrology and tectonic implications. J GEOL SOC LONDON 135, 219–28.CrossRefGoogle Scholar
Hall, J., Brewer, J. A., Matthews, D. H. & Warner, M. R. 1984. Crustal structure across the Caledonides from the ‘WINCH’ seismic reflection profile: influences on the evolution of the Midland Valley of Scotland. TRANS R SOC EDINBURGH EARTH SCI 75, 97–109.CrossRefGoogle Scholar
Hall, J., Powell, D. W., Warner, M. R., El-Ilsa, Z. H., Adesanya, O. & Bluck, B. J. 1983. Seismological evidence for shallow crystalline basement in the Southern Uplands of Scotland. NATURE 305, 418–20.CrossRefGoogle Scholar
Halliday, A. N. 1984. Coupled Sm–Nd and U–Pb systematics in late Caledonian granites and the basement under northern Britain. NATURE 307, 229–33.CrossRefGoogle Scholar
Halliday, A. N., Aftalion, M., Upton, B. G. J., Aspen, P. & Jocelyn, J. 1984. U–Pb isotopie ages from a granulite-facies xenolith from Partan Craig in the Midland Valley of Scotland. TRANS R SOC EDINBURGH EARTH SCI 75, 71–4.CrossRefGoogle Scholar
Halliday, A. N., Aftalion, M., van Breemen, O. & Jocelyn, J. 1979. Petrogenetic significance of Rb–Sr and U–Pb isotopie systems in the 400 Ma old British Isles granitoids and their hosts. In Harris, A. L., Holland, C. H. & Leake, B. E. (eds) The Caledonides of the British Isles—reviewed, 653–61. SPEC PUBL GEOL SOC LONDON 8.Google Scholar
Hamilton, P. J., Evensen, N. M., O'Nions, R. K. & Tarney, J. 1979. Sm–Nd systematics of Lewisian gneisses. NATURE 277, 25–8.CrossRefGoogle Scholar
Hamilton, P. J., O'Nions, R. K. & Pankhurst, R. J. 1980. Isotopie evidence for the provenance of some Caledonian granites. NATURE 287, 279–84.CrossRefGoogle Scholar
Lambert, R. St J. & Holland, J. G. 1972. A geochronological study of the Lewisian from Loch Laxford to Durness, Sutherland, Scotland. J GEOL SOC LONDON 128, 3–19.CrossRefGoogle Scholar
Lambert, R. St J., Myers, J. S. & Watson, J. 1970. An apparent age for a member of the Scourie dyke suite in Lewis, Outer Hebrides. SCOTT J GEOL 6, 221–5.CrossRefGoogle Scholar
Long, L. E. 1964. Rb–Sr chronology of the Cam Chuinneag intrusion, Ross-shire, Scotland. J GEOPHYS RES 69, 1589–97.CrossRefGoogle Scholar
Long, L. E. & Lambert, R. St J. 1963. Rb–Sr isotope ages from the Moine series. In Johnson, M. R. W. & Stewart, F. H. (eds) The British Caledonides, 217–47. Edinburgh: Oliver & Boyd.Google Scholar
Longman, C. D., Bluck, B. J. & van Breemen, O. 1979. Ordovician conglomerates and the evolution of the Midland Valley. NATURE 280, 578–81.CrossRefGoogle Scholar
Longman, C. D., Bluck, B. J., van Breemen, O. & Aftalion, M. 1982. Ordovician conglomerates: constraints on the timescale. In Odin, G. S. (ed.) Numerical dating in stratigraphy, 807–9. New York: John Wiley.Google Scholar
Lyon, T. D. B. & Bowes, D. R. 1977. Rb–Sr, U–Pb and K–Ar isotopie study of the Lewisian Complex between Durness and Loch Laxford, Scotland. KRYSTALINIKUM 13, 53–72.Google Scholar
Lyon, T. D. B., Gillen, B. and Bowes, D. R. 1975. Rb–Sr isotopie studies near the major Precambrian junction between Scourie and Loch Laxford, Northwest Scotland. SCOTT J GEOL 11, 333–7.CrossRefGoogle Scholar
Lyon, T. D. B., Pidgeon, R. T., Bowes, D. R. & Hopgood, A. M. 1973. Geochronological investigation of the quartzofeldspathic rocks of the Lewisian of Rona, Inner Hebrides. Q J GEOL SOC LONDON 129, 389–404.CrossRefGoogle Scholar
Moorbath, S. & Park, R. G. 1972. The Lewisian geochronology of the southern region of the Scottish mainland. SCOTT J GEOL 8, 51–74.CrossRefGoogle Scholar
Moorbath, S., Powell, J. L. & Taylor, P. N. 1975. Isotopie evidence for the age and origin of the “grey gneiss” complex of southern Outer Hebrides, Scotland. J GEOL SOC LONDON 131, 213–22.CrossRefGoogle Scholar
Moorbath, S. & Taylor, P. N. 1974. Lewisian age for the Scardroy mass. NATURE 250, 41–3.CrossRefGoogle Scholar
Moorbath, S., Welke, H. & Gale, N. H. 1969. The significance of lead isotope studies in ancient high grade metamorphic basement complexes, as exemplified by the Lewisian rocks of northwest Scotland. EARTH PLANET SCI LETT 6, 245–56.CrossRefGoogle Scholar
Pankhurst, R. J. 1970. The geochronology of the basic igneous complexes. SCOTT J GEOL 6, 83–107.CrossRefGoogle Scholar
Pankhurst, R. J. 1974. Rb–Sr whole-rock chronology of Caledonian events in Northeast Scotland. BULL GEOL SOC AM 85, 345–50.2.0.CO;2>CrossRefGoogle Scholar
Pankhurst, R. J. 1981. Isotope and trace element evidence for the origin and evolution of the Caledonian granites in the Scottish Highlands. In Atherton, M. P. & Tarney, J. (eds) Origin of granite batholiths: geochemical evidence, 18–33. Nantwich: Shiva.Google Scholar
Pankhurst, R. J. & Pidgeon, R. T. 1976. Inherited isotope systems and the source region pre-history of early Caledonian granites in the Dalradian Series of Scotland. EARTH PLANET SCI LETT 31, 55–68.CrossRefGoogle Scholar
Piasecki, M. A. J. 1980 New light on Moine rocks of the Central Highlands of Scotland. J GEOL SOC LONDON 137, 41–59.CrossRefGoogle Scholar
Piasecki, M. A. J. & van Breemen, O. 1979. The “Central Highland Granulites”: cover-basement tectonics in the Moine. In Harris, A. L., Holland, C. H. & Leake, B. E. (eds) The Caledonides of the British Isles—reviewed, 139–44. SPEC PUBL GEOL SOC LONDON 8.Google Scholar
Piasecki, M. A. J. & van Breemen, O. 1983. Field and isotopie evidence for a c. 750 Ma tectonothermal event in Moine rocks in the Central Highland region of the Scottish Caledonides. TRANS R SOC EDINBURGH EARTH SCI 73 (FOR 1982), 119–34.CrossRefGoogle Scholar
Piasecki, M. A. J., van Breemen, O. & Wright, A. E. 1981. Late Precambrian geology of Scotland, England and Wales. In Kerr, J. W. & Fergusson, A. J. (eds) Geology of the North Atlantic Borderlands, 57–94. MEM CAN SOC PET GEOL 7.Google Scholar
Pidgeon, R. T. & Aftalion, M. 1972. The geochronological significance of discordant U–Pb ages of oval-shaped zircons from a Lewisian gneiss from Harris, Outer Hebrides. EARTH PLANET SCI LETT 17, 269–74.CrossRefGoogle Scholar
Pidgeon, R. T. & Aftalion, M. 1978. Cogenetic and inherited zircon U–Pb systems in granites: Palaeozoic granites of Scotland and England. In Bowes, D. R. & Leake, B. E. (eds) Crustal evolution in northwestern Britain and adjacent regions, 183–220. GEOL J SPEC ISSUE 10.Google Scholar
Pidgeon, R. T. & Bowes, D. R. 1972. Zircon U–Pb ages of granulites from the Central Region of the Lewisian, northwestern Scotland. GEOL MAG 109, 247–58.CrossRefGoogle Scholar
Pidgeon, R. T. & Johnson, M. R. W. 1974. A comparison of zircon U–Pb and whole-rock Rb–Sr systems in three phases of the Cam Chuinneag granite, northern Scotland. EARTH PLANET SCI LETT 24, 105–12.CrossRefGoogle Scholar
Ramsay, D. M. & Sturt, B. A. 1979. The status of the Banff nappe. In Harris, A. L., Holland, C. H. & Leake, B. E. (eds) The Caledonides of the British Isles—reviewed, 145–51. SPEC PUBL GEOL SOC LONDON 8.Google Scholar
Silver, L. T. & Deutsch, S. 1963. Uranium-lead isotopie variations in zircons: A case study. J GEOL 71, 721–58.CrossRefGoogle Scholar
Smith, P. J. & Bott, M. H. P. 1975. Structure of the crust beneath the Caledonian Foreland and Caledonian Belt of the North Scottish Shelf Region. GEOPHYS J R ASTRON SOC 40, 187–205.CrossRefGoogle Scholar
Sturt, P. A., Ramsay, D. M., Pringle, I. R. & Teggin, D. E. 1977. Precambrian gneisses in the Dalradian sequence of North-East Scotland. J GEOL SOC LONDON 134, 41–4.CrossRefGoogle Scholar
Upton, B. G. J., Aspen, P., Graham, A. & Chapman, N. A. 1976. Pre-Palaeozoic basement of the Scottish Midland Valley. NATURE 260, 517–8.CrossRefGoogle Scholar
Upton, B. G. J., Aspen, P. & Hunter, R. H. 1984. Xenoliths and their implications for the deep geology of the Midland Valley of Scotland and adjacent regions. TRANS R SOC EDINBURGH EARTH SCI 75, 65–70.CrossRefGoogle Scholar
van Breemen, O., Aftalion, M., Bowes, D. R., Dudek, A., Mísař, Z., Povondra, P. & Vrána, S. 1982. Geochronological studies of the Bohemian massif, Czechoslovakia, and their significance in the evolution of Central Europe. TRANS R SOC EDINBURGH EARTH SCI 73, 89–108.CrossRefGoogle Scholar
van Breemen, O., Aftalion, M. & Johnson, M. R. W. 1979. Age of the Loch Borrolan complex, Assynt, and late movements along the Moine Thrust Zone. J GEOL SOC LONDON 136, 489–95.CrossRefGoogle Scholar
van Breemen, O., Aftalion, M., Pankhurst, R. J. & Richardson, S. W. 1979. Age of the Glen Dessary Syenite, Inverness-shire: diachronous Palaeozoic metamorphism across the Great Glen. SCOTT J GEOL 15, 49–62.CrossRefGoogle Scholar
van Breemen, O., Aftalion, M. & Pidgeon, R. T. 1971. The age of the granitic injection complex of Harris, Outer Hebrides. SCOTT J GEOL 7, 139–52.CrossRefGoogle Scholar
van Breemen, O. & Bluck, B. J. 1981. Episodic granite plutonism in the Scottish Caledonides. NATURE 291, 113–7.CrossRefGoogle Scholar
van Breemen, O. & Boyd, R. 1972. A radiometrie age for pegmatite cutting the Belhelvie mafic intrusion, Aberdeenshire. SCOTT J GEOL 8, 115–20.CrossRefGoogle Scholar
van Breemen, O., Halliday, A. N., Johnson, M. R. W. & Bowes, D. R. 1978. Crustal additions in late Precambrian times. In Bowes, D. R. & Leake, B. E. (eds) Crustal evolution in northwestern Britain and adjacent regions, 81–106, GEOL J SPEC ISSUE 10.Google Scholar
van Breemen, O. & Hawkesworth, C. J. 1980. Sm–Nd isotopie study of garnets and their metamorphic host rocks. TRANS R SOC EDINBURGH EARTH SCI 71, 97–102.CrossRefGoogle Scholar
van Breemen, O. & Piasecki, M. A. J. 1983. The Glen Kyllachy Granite and its bearing on the nature of the Caledonian Orogeny in Scotland. J GEOL SOC LONDON 140, 47–60.CrossRefGoogle Scholar
van Breemen, O., Pidgeon, R. T. & Johnson, M. R. W. 1974. Precambrian and Palaeozoic pegmatites in the Moines of northern Scotland. J GEOL SOC LONDON 130, 493–507.CrossRefGoogle Scholar
Wetherill, G. W. 1956. Discordant uranium lead ages. TRANS AM GEOPHYS UN 37, 320–6.Google Scholar
Wright, A. E. 1976. Alternating subduction direction and the evolution of the Atlantic Caledonides. NATURE 264, 156–60.CrossRefGoogle Scholar