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Hyalotuff deltaic deposits in the Ballantrae ophiolite of SW Scotland: evidence for crustal position of the lava sequence

Published online by Cambridge University Press:  03 November 2011

B. J. Bluck
Affiliation:
Department of Geology, University of Glasgow, Glasgow G12 8QQ, Scotland.

Abstract

Hyalotuff deltaic deposits, a high proportion of volcanogenic sediment and a repeated occurrence of conglomerate with well-rounded clasts constitute evidence for the shallow-water origin of spilitic lavas and volcanogenic sediments in an Ordovician ophiolite at Ballantrae, SW Scotland. One section, >1.5 km thick, shows repeated evidence for a shallow-water origin. This implies accumulation in a subsiding area. In this sense the sequence at Ballantrae is in marked contrast to those found in oceanic islands (hot spots) which are known to grow from deep into shallow water. Neither does it compare well with those from ocean ridges which usually begin in deep water and move, with cessation of vulcanicity, into even deeper water.

The lava sequence at Ballantrae compares well with oceanic island-arc and remnant arc deposits where uplift and subsidence is common. This, the occurrence of intermediate and acidic lavas and clasts, and the restricted palaeontological and radiometric ages support an arc-marginal basin origin for the lavas. Diversity in the chemical composition of the lavas may reflect diverse origins within the marginal basin.

An upward coarsening sedimentary sequence was built by a hyalotuff delta which formed in front of advancing lava flows. As the lavas advanced over the sediments so a sequence was generated where these sediments have a source in lava flows which were eventually to overlie them.

Clasts of tholeiite were derived from lavas which are now spilite. This, together with the presence of spilitic lava clasts and tuff immediately beneath the flow suggests that the spilitisation resulted from metasomatic activity associated with the convective circulation of trapped water, with the lava as a heat source.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1982

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References

Bailey, E. B. & McCallien, W. J. 1957. The Ballantrae serpentinite, Ayrshire. TRANS GEOL SOC EDINBURGH 17, 3353.CrossRefGoogle Scholar
Ballard, R. D. & Moore, J. D. 1977. Photographic atlas of the Mid-Atlantic Ridge rift valley. New York: Springer-Verlag.CrossRefGoogle Scholar
Balsillie, D. 1932. The Ballantrae igneous complex. S. Ayrshire. GEOL MAG 69, 107–31.CrossRefGoogle Scholar
Bluck, B. J. 1969. Particle rounding in beach gravels. GEOL MAG 106, 114.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., Halliday, A. N., Aftalion, M. & MacIntyre, R. M. 1980. Age and origin of Ballantrae ophiolite, its significance to Caledonian orogen and Ordovician time scale. GEOLOGY 8, 492–95.2.0.CO;2>CrossRefGoogle Scholar
Bryan, W. B. 1972. Morphology of quench crystals in submarine basalts. J GEOPHYS RES 177, 5812–9.CrossRefGoogle Scholar
Carlisle, D. 1963. Pillow breccias and their aquagene tuffs, Quadra Island, British Columbia. J GEOL 71, 4871.CrossRefGoogle Scholar
Coombs, D. S. 1974. On mineral facies of spilitic rocks and their genesis. In Amstutz, G. C. (ed.) Spilites and spilitic rocks, 373–85. Berlin: Springer Verlag.CrossRefGoogle Scholar
Dewey, J. F., Richards, R. B. & Skevington, D. 1970. New light on the age of Dalradian deformation and metamorphism in Western Ireland. NOR GEOL TIDDSKR 50 1944.Google Scholar
Dimroth, E. 1977. Archean subaqueous tuffs, autoclastic volcanic rocks. Rouyn-Noranda area, Quebec: classification, diagenesis and interpretation. REP ACT PART A GEOL SURV CANADA 77–1A, 513–22.Google Scholar
Dimroth, E., Cousineau, P., Leduc, M. & Sanschagrin, Y. 1978. Structure and organisation of Archean subaquenous basalt flows. Rouyn-Noranda, Quebec Canada. CAN J EARTH SCI 15, 902–18.CrossRefGoogle Scholar
Dobkins, J. E. & Folk, R. L. 1970. Shape development on Tahiti-Nui. J SEDIMENT PETROL 40, 1167–203.Google Scholar
Furnes, H. & Fridleifsson, I. B. 1974. Tidal effects on the formation of pillow lava/hyaloclastite deltas. GEOLOGY 1 381–4.2.0.CO;2>CrossRefGoogle Scholar
Hall, J. M. & Robinson, R. J. 1979. Deep crustal drilling in the North Atlantic. SCIENCE 204, 573–86.Google Scholar
Heiken, G. 1974. An atlas of volcanic ash. SMITHSONIAN CONTRIB EARTH SCI 12, 1101.Google Scholar
Honnorez, J. & Kirst, P. 1975. Submarine basaltic volcanism: morphometric parameters for discriminating hyaloclastites from hyalotuffs. BULL VOLCANOL 39, 442–65.Google Scholar
Jackson, E. D., Koizumi, I.et al. 1980. Introduction and summary of results from DSDP Leg 55, the Hawaiian-Emperor hot-spot experiment. In Jackson, E. D., Koizumi, I.et al. Init. Reps of DSDP 55, 531Washington: U.S. Govt Printing Office.Google 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.CrossRefGoogle Scholar
Jones, J. G. 1969. Pillow lavas as depth indicators. AM J SCI 267, 181–95.CrossRefGoogle Scholar
Jones, J. G. 1970. Intraglacial volcanoes of the Langervatn region, south-west Iceland. J GEOL 78, 127–40.CrossRefGoogle Scholar
Kroenke, L., Scott, R.et al. 1980. Site 451: east edge of west Mariana ridge. In Kroenke, L., Scott, R.et al. Init. Reps DSDP 59, 405–83 Washington: U.S. Govt Printing Office.Google Scholar
Kuniyoshi, S. & Liou, J. G. 1976. Burial metamorphism of the Karmutsen volcanic rocks, Northwestern Vancouver Island, British Columbia. AM J SCI 276, 1096–119.Google Scholar
Lewis, A. D. & Bloxam, T. W. 1977. Petrotectonic environments of the Girvan-Ballantrae lavas from rare-earth element distributions. SCOTT J GEOL 13, 211–22.Google Scholar
Lewis, A. D. & Bloxam, T. W. 1980. Basaltic macadam-breccias in the Girvan-Ballantrae Complex, Ayrshire. SCOTT J GEOL 16, 181–7.CrossRefGoogle Scholar
Mattey, D. P., Marsh, N. G. & Tarney, J. 1980. The geochemistry, mineralogy, and petrology of basalts from the west Philippine and Parece Vela basins and from the Palau-Kyushu and west Mariana ridges. Deep Sea Drilling Project Leg 59. In Kroenke, L., Scott, R.et al. Init. Reps DSDP 59, 753–97. Washington: U.S. Govt Printing Office.Google Scholar
McBirney, A. R. 1963. Factors governing the nature of submarine volcanism. BULL VOLCANOL 26, 455–69.CrossRefGoogle Scholar
McBirney, A. R. & Williams, H. 1968. Geology and petrology of the Galápagos Islands. GEOL SOC AM MEM 118, 1197.Google Scholar
Mitchell, A. H. G. 1970. Facies of an early Miocene volcanic arc, Malekula Island, New Hebrides. SEDIMENTOLOGY 14, 201–43.CrossRefGoogle Scholar
Moore, J. G. 1979. Vesicularity and CO2 in mid-ocean ridge basalts. NATURE LONDON 282, 250–3.Google Scholar
Moore, J. G., Phillips, R. L., Grigg, R. W., Paterson, D. W. & Swanson, D. A. 1973. Flow of lava into the sea. 1969–71, Kilanea Volcano, Hawaii. BULL GEOL SOC AM 84, 537–46.Google Scholar
Moore, J. G. & Schilling, J. G. 1973. Vesicles, water and sulphur in Reykjanes Ridge basalt. CONTRIB MINERAL PETROL 41, 105–18.CrossRefGoogle Scholar
Norrman, J. O. 1970. Trends in post-volcanic development of Surtsey Island. Progress Report on geomorphological activities in 1968. SURTSEY RES PROG REP, 5, 95112.Google Scholar
Peach, B. N. & Home, J. 1899. The Silurian rocks of Great Britain 1, Scotland. MEM GEOL SURV U K.Google Scholar
Seyfried, W. E., Mottl, M. J. & Bischoff, J. L. 1978. Seawater/basalt ratio effects on the chemistry and mineralogy of spilites from the ocean floor. NATURE LONDON 275, 211–3.Google Scholar
Sukheswala, R. N. 1974. Gradation of tholeiitic Deccan basalt into spilite, Bombay, India. In Amstutz, G. C. (ed.) Spilites and spilitic rocks, 229–50. Berlin: Springer-Verlag.CrossRefGoogle Scholar
Tasse, N., Lajoie, J. & Dimroth, E. 1978. The anatomy and interpretation of an Archean volcaniclastic sequence, Noranda region, Quebec. CAN J EARTH SCI 15, 585–97.CrossRefGoogle Scholar
Thorarinsson, S. 1966. Surtsey, the New Island in the North Atlantic. New York: Viking Press.Google Scholar
Weissel, J. K. 1981. Magnetic lineations in marginal basins of the Western Pacific. PHILOS TRANS R SOC LONDON A300, 223–47.Google Scholar
Wilkinson, J. M. & Cann, J. R. 1974. Trace elements and tectonic relationships of basaltic rocks in Ballantrae Igneous Complex Ayrshire. GEOL MAG 11, 3541.CrossRefGoogle Scholar