Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-25T08:25:46.322Z Has data issue: false hasContentIssue false

Geochemistry of peridotites, gabbros and trondhjemites of the Ballantrae complex, SW Scotland

Published online by Cambridge University Press:  03 November 2011

E. Jelínek
Affiliation:
Department of Mineralogy and Geochemistry, Charles University, Albertov 6, 128 43 Prague 2, Czechoslovakia.
J. Souček
Affiliation:
Department of Petrology, Charles University, Albertov 6, 128 43 Prague 2, Czechoslovakia.
Z. Řanda
Affiliation:
Institue of Raw Materials, Vrbový Mlýn, Žižkov 83, 28 400 Kutná Hora, Czechoslovakia.
P. Jakeš
Affiliation:
Geological Survey of Czechoslovakia, Malostranské nam. 19, 118 21 Prague 1, Czechoslovakia.
B. J. Bluck
Affiliation:
Department of Geology, University of Glasgow, Glasgow G12 8QQ, Scotland.
D. R. Bowes
Affiliation:
Department of Geology, University of Glasgow, Glasgow G12 8QQ, Scotland.

Abstract

Major and trace element, including REE, analytical data are used as bases for interpreting the petrogenesis of the major igneous components of the northern part of the Ballantrae complex which occurs in the southwestern part of the Midland Valley of Scotland. Most of the peridotite, now serpentinised, is similar to ultramafic rocks in other ophiolite complexes. Mean crystallisation conditions, determined on the basis of co-existing orthopy-roxenes and clinopyroxenes for the dominant peridotite and minor pyroxenite were 1060 (±60)°C—20 (±2) kb and 1240 (±89)°C—25 (±25) kb, respectively. These rocks, of mantle provenance, have compositions consistent with being residues after the extraction of 20–30% of tholeiitic material from the mantle. The presence among them of a rock whose REE contents indicate that it is a plagioclase peridotite, point to the tectonic incorporation of the products of a high level magma chamber.

The mafic parts of the complex have tholeiitic characteristics and developed between 1300° and 1100°C. They do not represent primary mantle melt but fractionated material. Clinopyroxene was the main fractionating phase and more than 10% fractional crystallisation is indicated with increase from gabbros, through beerbachites (metadolerites) of a sheeted dyke complex and pillow lavas, to microgabbros and pyroxene diorites. Biotite diorites and trondhjemites represent the most fractionated products, the latter having affinities with ophiolitic plagiogranites.

The beerbachites of the sheeted dyke complex do not all represent the same stage of fractionation. The pillow lavas have REE patterns similar to rocks found in marginal basins but are markedly different from pillow lavas from the Highland Border Complex in Arran, near the northern margin of the Midland Valley.

Type
Midland Valley
Copyright
Copyright © Royal Society of Edinburgh 1984

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

Aftalion, M., van Breemen, O. & Bowes, D. R. 1984. Age constraints on basement of the Midland Valley of Scotland. TRANS R SOC EDINBURGH EARTH SCI 75, 5364.CrossRefGoogle Scholar
Alabaster, T., Pearce, J. A. & Malpas, J. 1982. The volcanic stratigraphy and petrogenesis of the Oman ophiolite complex. CONTRIB MINERAL PETROL 81, 168–83.Google Scholar
Balsillie, D. 1932. The Ballantrae Igneous Complex, South Ayrshire. GEOL MAG 69, 107–31.Google Scholar
Balsillie, D. 1937. Further observations on the Ballantrae Igneous Complex, South Ayrshire. GEOL MAG 74, 2033.Google Scholar
Bloxam, T. W. 1955. The origin of the Girvan–Ballantrae beerbachites. GEOL MAG 92, 329–36.CrossRefGoogle Scholar
Bloxam, T. W. 1968. The petrology of Byne Hill, Ayrshire. TRANS R SOC EDINBURGH 68, 105–22.Google Scholar
Bloxam, T. W. 1981. Trondhjemite in the Girvan–Ballantrae complex, Ayrshire, Scotland. J GEOL 89, 754–64.CrossRefGoogle Scholar
Bloxam, T. W. & Allen, J. B. 1960. Glaucophane schist, eclogite and associated rocks from Knockormal in the Girvan–Ballantrae complex, South Ayrshire. TRANS R SOC EDINBURGH 64, 129.CrossRefGoogle Scholar
Bloxam, T. W. & Lewis, A. D. 1972. Ti, Zr and Cr in some British pillow lavas and their petrogenetic affinities. NATURE PHYS SCI 237, 134–6.CrossRefGoogle Scholar
Bluck, B. J. 1978. Geology of a continental margin 1: the Ballantrae complex. In Bowes, D. R. & Leake, B. E. (eds) Crustal evolution in northwestern Britain and adjacent regions, 151–62. GEOL J SPEC ISSUE 10.Google Scholar
Bluck, B. J. 1982. Hyalotuff deltaic deposits in the Ballantrae ophiolite of SW Scotland: evidence for crustal position of the lava sequence. TRANS R SOC EDINBURGH EARTH SCI 72 (FOR 1981), 217–28.CrossRefGoogle Scholar
Bluck, B. J. 1984. Pre-Carboniferous history of the Midland Valley of Scotland. TRANS R SOC EDINBURGH EARTH SCI 75, 275–95.Google Scholar
Bluck, B. J., Halliday, A. N., Aftalion, M. & Macintyre, R. M. 1980. Age and origin of Ballantrae ophiolite and its significance to the Caledonian orogeny and Ordovician time scale. GEOLOGY 8, 492–5.Google Scholar
Church, W. R. & Gayer, R. A. 1973. The Ballantrae ophiolite. GEOL MAG 110, 497510.CrossRefGoogle Scholar
Coleman, R. G. 1977. Ophiolites—Ancient Oceanic Lithosphere? Berlin: Springer-Verlag.CrossRefGoogle Scholar
Dewey, J. F. 1974. Continental margins and ophiolite obduction: Appalachian Caledonian system. In Burk, C. A. & Drake, C. L. (eds) Geology of continental margins, 933–50. New York: Springer.Google Scholar
Dupuy, C., Dostal, J. & Le Blanc, M. 1981. Geochemistry of an ophiolite complex from New Caledonia. CONTRIB MINERAL PETROL 76, 7783.CrossRefGoogle Scholar
Hamilton, P. J., Bluck, B. J. & Halliday, A. N. 1984. Sm-Nd ages from the Ballantrae complex, SW Scotland. TRANS R SOC EDINBURGH EARTH SCI 75, 183–7.CrossRefGoogle Scholar
Hanson, G. N. & Langmuir, C. H. 1978. Modelling of major elements in mantle-melt systems using trace element approaches. GEOCHIM COSMOCHIM ACTA 42, 725–41.CrossRefGoogle Scholar
Holub, F. V., Klápová, H., Bluck, B. J. & Bowes, D. R. 1984. Petrology and geochemistry of post-obduction dykes of the Ballantrae complex, SW Scotland. TRANS R SOC EDINBURGH EARTH SCI 75, 211–23.CrossRefGoogle Scholar
Jamieson, R. A. 1981. Metamorphism during ophiolite emplacement—the petrology of the St. Anthony complex. J PETROL 22, 397449.Google Scholar
Jaques, A. L. 1981. Petrology and petrogenesis of cumulate peridotites and gabbros from the Marum ophiolite complex, northern Papua, New Guinea. J PETROL 22, 140.CrossRefGoogle Scholar
Jaques, A. L. & Chappell, B. W. 1980. Petrology and trace element geochemistry of the Papuan ultramafic belt. CONTRIB MINERAL PETROL 75, 5570.CrossRefGoogle Scholar
Jelínek, E., Souček, J., Bluck, B. J., Bowes, D. R. & Treloar, P. J. 1980. Nature and significance of beerbachites in the Ballantrae ophiolite, SW Scotland. TRANS R SOC EDINBURGH EARTH SCI 71, 159–79.Google Scholar
Kern, H. 1968. Zur geochemie und Lagerstätten kunde des Chroms und zur Microskopie und Genese des Chromerze. Berlin: Gebrüder Borntraeger.Google Scholar
Le Bas, M. J. 1962. The role of aluminium in igneous clinopyroxenes with relation to their parentage. AM J SCI 260, 267–88.CrossRefGoogle Scholar
Leake, B. E. 1978. Nomenclature of amphiboles. CAN MINERAL 16, 501–20.Google Scholar
Lewis, A. D. & Bloxam, T. W. 1977. Petrotectonic environments of the Girvan–Ballantrae lavas from rare-earth element distribution. SCOTT J GEOL 13, 211–22.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.Google Scholar
Mercier, J. C. C. 1976. Single pyroxene geothermometry and geobarometry. AM MINERAL 61, 603–15.Google Scholar
Melka, K. 1965. Classification of chlorite minerals (in Czech). VESTN USTR USTAVU GEOL 40, 23–7.Google Scholar
Montigny, R., Bougault, H., Bottinga, Y. & Allegre, C. J. 1973. Trace element geochemistry and genesis of the Pindos ophiolite suite. GEOCHIM COSMOCHIM ACTA 37, 2135–47.Google Scholar
Mori, T. 1977. Geochemistry of spinel lherzolites. CONTRIB MINERAL PETROL 59, 261–79.CrossRefGoogle Scholar
Nisbet, E. G. & Pearce, J. A. 1977. Clinopyroxene composition in mafic lavas from different tectonic settings. CONTRIB MINERAL PETROL 63, 149–60.CrossRefGoogle Scholar
Řanda, Z., Benada, J., Kuncíř, J., Vobecký, M. & Frána, J. 1972. Radioanalytical methods for non-destructive analysis of lunar samples. J RADIO ANAL CHEM 11, 305–37.CrossRefGoogle Scholar
Rivalenti, G., Garuti, G., Rossi, A., Siena, F. & Sinigoi, S. 1981. Existence of different peridotite types and of a layered igneous complex in the Ivrea zone of the Western Alps. J PETROL 22, 127–53.Google Scholar
Saunders, A. D., Tarney, J., Stem, C. S. & Dalziel, I. W. D. 1979. Geochemistry of Mesozoic marginal basin floor igneous rocks from southern Chile. BULL GEOL SOC AM 90, 237–58.Google Scholar
Sigurdsson, H. & Schilling, J. G. 1976. Spinels in Mid-Atlantic Ridge basalts: chemistry and occurrence. EARTH PLANET SCI LETT 29, 720.Google Scholar
Skinner, W. R., Bowes, D. R. & Skinner, D. L. 1978. Petrochemistry of chromite-bearing ultramafic complexes, Red Lodge, Montana, U.S.A. In Verwoerd, W. J. (ed.) Mineralization in Metamorphic Terranes, 509–27. Pretoria: van Schaik.Google Scholar
Stone, P. & Rushton, A. W. A. 1983. Graptolite faunas from the Ballantrae ophiolite complex and their structural implications. SCOTT J GEOL 19, 297310.CrossRefGoogle Scholar
Suen, C. J., Frey, F. A. & Malpas, J. 1979. Bay of Islands ophiolite suite, Newfoundland: petrologie and geochemical characteristics with emphasis on rare earth element geochemistry. EARTH PLANET SCI LETT 45, 337–48.Google Scholar
Thirlwall, M. F. & Bluck, B. T. 1984. Sr-Nd isotope and geochemical evidence that the Ballantrae Ophiolite', SW Scotland, is polygenetic. In Gass, I. G., Lippard, S. J. & Shelton, A. W. (eds) Ophiolites and oceanic lithosphere, 215–30. GEOL SOC LONDON SPEC PUBL 13.Google Scholar
Treloar, P. J., Bluck, B. J., Bowes, D. R. & Dudek, A. 1980. Hornblende-garnet metapyroxenite beneath serpentinite in the Ballantrae complex of SW Scotland and its bearing on the depth provenance of obducted oceanic lithosphere. TRANS R SOC EDINBURGH EARTH SCI 71, 201–12.CrossRefGoogle Scholar
Wells, P. R. A. 1977. Pyroxene thermometry in simple and complex systems. CONTRIB MINERAL PETROL 62, 129–39.Google Scholar
Wilkinson, J. M. & Cann, J. R. 1974. Trace elements and tectonic relationships of basaltic rocks in the Ballantrae igneous complex, Ayrshire. GEOL MAG 111, 3541.Google Scholar
Wood, B. J. & Banno, S. 1973. Garnet–orthopyroxene and orthopyroxene-clinopyroxene relationships in simple and complex systems. CONTRIB MINERAL PETROL 42, 109–24.Google Scholar