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Silurian subduction-related assembly of fault-defined tracts at the Laurieston Fault, Southern Uplands accretionary terrane, Scotland, U.K.

Published online by Cambridge University Press:  03 November 2011

M. C. Akhurst ,
A. A. McMillan ,
G. S. Kimbell ,
P. Stone  and
R. J. Merriman
M. C. Akhurst
Affiliation:
M. C. Akhurst, A. A. McMillan and P. Stone, British Geological Survey, Murchison House, West Mains Road, Edinburgh, EH9 3LA, UK.
A. A. McMillan
Affiliation:
M. C. Akhurst, A. A. McMillan and P. Stone, British Geological Survey, Murchison House, West Mains Road, Edinburgh, EH9 3LA, UK.
G. S. Kimbell
Affiliation:
G. S. Kimbell and R. J. Merriman, British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK.
P. Stone
Affiliation:
M. C. Akhurst, A. A. McMillan and P. Stone, British Geological Survey, Murchison House, West Mains Road, Edinburgh, EH9 3LA, UK.
R. J. Merriman
Affiliation:
G. S. Kimbell and R. J. Merriman, British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK.
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Abstract

ABSTRACT

Subduction-related accretion of fault-defined tracts built up the Southern Uplands terrane during the final stages of closure of the Iapetus Ocean (Llandovery to Wenlock). Contrasts in depositional environment and pronounced differences in geochemical composition, provenance studies and metamorphic grade across the Laurieston Fault between the Gala and Hawick groups, suggests that it has a greater regional significance than most other tract-bounding structures. Initiated by underthrusting, and acting as a locus for subsequent sinistral strike-slip, the fault overlies a regional gravity anomaly gradient that is interpreted to be due, in part, to a concealed NW-ward dipping shallow basement surface. This is modelled as an open ramp in the NE that steepens to a near-vertical step along-strike to the SW. A change in structural geometry noted at the Laurieston Fault, with excision of accretionary tracts, is related to a period of oblique closure of the Iapetus Ocean. The youngest Gala Group tracts were accreted during a period of intense transpression to form a regional strike-slip duplex over the shallow basement ramp with termination of the tracts at the Laurieston Fault, its surface expression. The ramp acted as an obstacle to forward-breaking thrust progress, forcing the out-of-sequence thrusting and repetitive thrust imbrication noted in the eastern Southern Uplands. Upper Palaeozoic reactivation of this basement structure may have transferred strain between extensional Permian basins.

Keywords

biostratigraphyduplex structureGala GroupgeochemistrygeophysicsHawick Groupillite crystallinityNd isotopesprovenancesedimentology
Type
Research Article
Information
Earth and Environmental Science Transactions of The Royal Society of Edinburgh , Volume 91 , Issue 3-4: The Southern Uplands Terrane: Tectonics and Biostratigraphy within the Caledonian Orogen , 2000 , pp. 435 - 446
Copyright
Copyright © Royal Society of Edinburgh 2000

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References

Akhurst, M. C. 1996. Shawhead, Crocktford: Gala and Hawick groups, sculptures and monuments. In Stone, P. (ed.) Geology in south-west Scotland: an excursion guide. Keyworth, Nottingham: British Geological Survey.Google Scholar
Anderson, T. B. 1987. The onset and timing of Caledonian sinistral shear in County Down. Journal of the Geological Society, London 144, 817–25.CrossRefGoogle Scholar
Anderson, T. B. & Oliver, G. J. H. 1986. The Orlock Bridge Fault: A major late Caledonian sinistral fault in the Southern Uplands terrane, British Isles. Transactions of the Royal Society of Edinburgh: Earth Sciences 77, 203–22.CrossRefGoogle Scholar
Barnes, R. P. 1989. Geology of the Whithorn district, Memoir of the British Geological Survey, Sheet 2 (Scotland). London: HMSO for British Geological Survey.Google Scholar
Barnes, R. P. in press. Geology of Kirkcowan, Wigtown and Whithorn district. Memoir of the British Geological Survey, Sheets 4W, 4E and 2 (Scotland).Google Scholar
Barnes, R. P., Anderson, T. B. & McCurry, J. A. 1987. Along-strike variation in the stratigraphical and structural profile of the Southern Uplands Central Belt in Galloway and Down. Journal of the Geological Society, London 144, 807–16.CrossRefGoogle Scholar
Barnes, R. P., Lintern, B. C. & Stone, P. 1988. Comment on: Soper, N. J., Webb, B. C. & Woodcock, N. H. 1987. Late Caledonian (Acadian) transpression in north-west England: timing, geometry and geotectonic significance. Proceedings of the Yorkshire Geological Society 47, 177–8.CrossRefGoogle Scholar
Barnes, R. P., Lintern, B. C. & Stone, P. 1989. Timing and regional implications of deformation in the Southern Uplands of Scotland. Journal of the Geological Society, London 146, 905–908.CrossRefGoogle Scholar
Barnes, R. P. & Stone, P. 1999. Trans-Iapetus contrasts in the geological development of southern Scotland (Laurentia) and the Lakesman Terrane (Avalonia). In Woodcock, N. H., Quirk, D. G., Fitches, W. R. & Barnes, R. P. (eds) In sight of the suture: the Palaeozoic geology of the Isle of Man in its Iapetus Ocean context, Geological Society, London, Special Publication 160, 307–23.Google Scholar
Bluck, B. J., Gibbons, W. & Ingham, J. K. 1992. Terranes. In Cope, J. C. W., Ingham, J. K. & Rawson, P. F. (eds) Atlas of palaeogeography and lithofacies, Geological Society, London, Memoir 13, 1–4.CrossRefGoogle Scholar
Bouma, A. H. 1962. Sedimentology of some flysch deposits: a graphic approach to interpretation. Amsterdam: Elsevier.Google Scholar
British Geological Survey. 1992a. The Rhins of Galloway. Scotland, Sheets 1 and 3 with parts of 7 and 4W. Solid Geology. 1:50 000. Keyworth, Nottingham: British Geological Survey.Google Scholar
British Geological Survey. 1992b. Kirkcowan Scotland. Sheet 4W. Solid Geology 1:50 000. Keyworth, Nottingham: British Geological Survey.Google Scholar
British Geological Survey. 1992c. Wigtown Scotland. Sheet 4E. Solid Geology 1:50 000. Keyworth, Nottingham: British Geological Survey.Google Scholar
British Geological Survey. 1993. Regional geochemistry of southern Scotland and part of northern England. Keyworth, Nottingham: British Geological Survey.Google Scholar
British Geological Survey. 1996. Thornhill. Scotland Sheet 9E. Solid Geology. 1:50 000. Keyworth, Nottingham: British Geological Survey.Google Scholar
British Geological Survey. 1998. New Galloway. Scotland Sheet 9W. Solid Geology. 1:50 000. Keyworth, Nottingham: British Geological Survey.Google Scholar
Davies, P. 1988. The sedimentology and geotectonic significance of upper Ordovician and lower Silurian sand-bodies in the Rhinns of Galloway and adjacent areas, southwest Scotland (Unpublished Ph.D. Thesis, University of Keele).Google Scholar
Davies, P. 1990. The geology of the Rhins of Galloway, SW Scotland: the west coast between Killantringan Bay and Clanyard Bay. British Geological Survey Technical Report, WA/90/67. Keyworth, Nottingham: British Geological Survey.Google Scholar
Floyd, J. D. 1996. Lithostratigraphy of the Ordovician rocks in the Southern Uplands: Crawford Group, Moffat Shale Group, Leadhills Supergroup. Transactions of the Royal Society of Edinburgh: Earth Sciences 86, 153–65.CrossRefGoogle Scholar
Floyd, J. D. 1999. Geology of the Carrick—Loch Doon district, Sheets 8W and 8E (Scotland). Memoir of the British Geological Survey. London: The Stationery Office.Google Scholar
Floyd, J. D. 2001. The Southern Uplands Terrane: a stratigraphical review. Transactions of the Royal Society of Edinburgh: Earth Sciences 91 (for 2000), 349–62.CrossRefGoogle Scholar
Fortey, R. A., Harper, D. A. T., Ingham, J. K., Owen, A. W. & Rushton, A. W. A. 1995. A revision of Ordovician series and stages from the historical type area. Geological Magazine 132, 15–30.CrossRefGoogle Scholar
Garver, J. I., Royce, P. R. & Smick, T. A. 1996. Chromium and nickel in shale of the Taconic foreland: a case study for the provenance of fine-grained sediments with an ultramafic source. Journal of Sedimentary Research 66, 100–106.Google Scholar
Geike, A., Horne, J., Skae, H. M. & Campbell, C. 1877. Explanation of Sheet 9, Kirkcudbrightshire (north-east part) and Dumfriesshire (south-west part). Memoir of the Geological Survey, Scotland.Google Scholar
Halliday, A. N., Stephens, W. E. & Harmon, R. S. 1980. Rb–Sr and O isotopic relationships in 3 zoned Caledonian granitic plutons, Southern Uplands, Scotland: evidence for varied sources and hybridization of magmas. Journal of the Geological Society, London 137, 329–18.CrossRefGoogle Scholar
Hipkin, R. G. & Hussain, A. 1983. Regional gravity anomalies: 1 Northern Britain. Report of the Institute of Geological Sciences 82/10.Google Scholar
Kassi, A. M. & Weir, J. A. 1993. Depositional and geotectonic history of the Gala area, eastern Southern Uplands, Scotland. Transactions of the Royal Society of Edinburgh: Earth Sciences 84, 161–73.CrossRefGoogle Scholar
Kelling, G., Davies, P. & Holroyd, J. 1987. Style, scale and significance of sand bodies in the Northern and Central Belts, southwest Southern Uplands. Journal of the Geological Society, London 144, 787–805.CrossRefGoogle Scholar
Kimbell, G. S. & Stone, P. 1995. Crustal magnetisation variations across the Iapetus Suture Zone. Geological Magazine 132, 599–609.CrossRefGoogle Scholar
Kneller, B. C. 1991. A foreland basin on the southern margin of the Iapetus. Journal of the Geological Society, London 148, 204–10.CrossRefGoogle Scholar
Lagios, E. & Hipkin, R. G. 1979. The Tweeddale Granite—a newly discovered batholith in the Southern Uplands. Nature 280, 672–5.CrossRefGoogle Scholar
Lapworth, C. 1870. On the Lower Silurian rocks of Galashiels. Geological Magazine 7, 204-209; 279–84.CrossRefGoogle Scholar
Lapworth, C. & Wilson, J. 1871. On the Silurian Rocks of the Counties of Roxburgh and Selkirk. Geological Magazine 8, 456–4.CrossRefGoogle Scholar
Leeder, M. R. 1982. Sedimentology—Process and product. London: George Allen & Unwin.Google Scholar
Leggett, J. K., McKerrow, W. S. & Eales, M. H. 1979. The Southern Uplands of Scotland: a Lower Palaeozoic accretionary prism. Journal of the Geological Society, London 136, 755–70.CrossRefGoogle Scholar
Lintern, B. C. & Floyd, J. D. 2000. Geology of the Kirkcudbright-Dalbeattie district, Sheets 5W, 5E and part of 6W (Scotland). Memoir of the British Geological Survey.Google Scholar
Loydell, D. K. 1998a. Early Silurian sea-level changes. Geological Magazine 135, 447–71.CrossRefGoogle Scholar
Loydell, D. K. 1998b. Llandovery graptolite biostratigraphy, Southern Uplands, Scottish 1:50 000 Sheet 5. British Geological Survey Technical Report, WH/98/185R.Google Scholar
McCurry, J. A. 1989. The geology of the Lower Palaeozoic rocks in the Mull of Galloway SW Scotland: studies in an imbricate thrust terrane. (Unpublished Ph.D. Thesis, University of St Andrews).Google Scholar
McCurry, J. A. 1990. The geology of the Rhins of Galloway south of the Portayew area. British Geological Survey Technical Report, WA/90/66.Google Scholar
McCurry, J. A. & Stone, P. 1996. Rhins of Galloway: a coastal traverse across the northern and central belts of the Southern Uplands. In Stone, P. (ed.) Geology in south-west Scotland: an excursion guide. Keyworth, Nottingham: British Geological Survey.Google Scholar
McKerrow, W. S., Leggett, J. K. & Eales, M. H. 1977. Imbricate thrust model of the Southern Uplands of Scotland. Nature, London 267, 237–9.CrossRefGoogle Scholar
McMillan, A. A. in press. Geology of the New Galloway and Thornhill district. Memoir of the British Geological Survey, Sheets 9W and 9E (Scotland).Google Scholar
Mackie, W. 1929. Preliminary report on the heavy minerals of the Silurian rocks of the Southern Uplands. Report of the British Association for the Advancement of Science, Glasgow 1928, 556.Google Scholar
Maddox, S. J., Blow, R. A. & O'Brien, S. R. 1997. The geology and hydrocarbon prospectivity of the North Channel Basin. In Meadows, N. S., Trueblood, S. P., Hardman, M. & Cowan, G. (eds) Petroleum Geology of the Irish Sea and Adjacent Areas. Geological Society, London, Special Publication 124, 95–111.CrossRefGoogle Scholar
Merriman, R. J. & Frey, M. 1999. Patterns of very low-grade metamorphism in metapelitic rocks. In Frey, M. & Robinson, D. (eds) Low-Grade Metamorphism, pp. 61–107. Oxford: Blackwell.Google Scholar
Merriman, R.J.& Roberts, B. 2001. Low-grade metamorphism in the Southern Uplands: deciphering the patterns of accretionary burial, shearing and cryptic aureoles. Transactions of the Royal Society of Edinburgh: Earth Sciences 91 (for 2000), 521–37.CrossRefGoogle Scholar
Morris, J. 1987. The Northern Belt of the Longford-Down Inlier, Ireland and Southern Uplands, Scotland: an Ordovician back-arc basin. Journal of the Geological Society, London 144, 773–86.CrossRefGoogle Scholar
Mutti, E & Lucchi, F.Ricci 1972. Le torbiditi dell'Apennino settentrionale: introduzione all'analisi de facies. Memoir Geological Society Italy 11, 161–1991978 English translation by T. H. Nilsen, International Geological Reviews 20, 125-66.Google Scholar
Peach, B. N. & Home, J. 1899. The Silurian Rocks of Britain, Volume 1. Scotland. Memoirs of the Geological Survey of the United Kingdom. Glasgow: HMSO.Google Scholar
Postma, G., Nemec, W. & Kleinspehn, K. L. 1988. Large floating clasts in turbidites: a mechanism for their emplacement. Sedimentary Geology 58, 47–61.CrossRefGoogle Scholar
Rushton, A. W. A., Stone, P. & Hughes, R. A. 1996. Biostratigraphical control of thrust models for the Southern Uplands of Scotland. Transactions of the Royal Society of Edinburgh: Earth Sciences 86 (for 1995), 137–52.CrossRefGoogle Scholar
Rust, B. R. 1965. The stratigraphy and structure of the Whithorn area of Wigtownshire, Scotland. Scottish Journal of Geology 1, 101–33.CrossRefGoogle Scholar
Shelton, R. 1997. Tectonic evolution of the Lame Basin. In Meadows, N. S., Trueblood, S. P., Hardman, M. & Cowan, G. (eds) Petroleum Geology of the Irish Sea and Adjacent Areas, Geological Society, London, Special Publication 124, 113–33.CrossRefGoogle Scholar
Soper, N. J., England, R. W., Snyder, D. W. & Ryan, P. D. 1992. The Iapetus suture zone in England, Scotland and eastern Ireland: a reconciliation of geological and deep seismic data. Journal of the Geological Society, London 149, 697–700.CrossRefGoogle Scholar
Soper, N. J. & Woodcock, N. H. 1990. Silurian collision and sediment dispersal patterns in southern Britain. Geological Magazine 127, 527–2.CrossRefGoogle Scholar
Stone, P. 1995. Geology of the Rhins of Galloway district. Memoir of the British Geological Survey, Sheets 1 and 3 (Scotland).Google Scholar
Stone, P., Floyd, J. D., Barnes, R. P. and Lintern, B. C. 1987. A sequential back-arc and foreland basin thrust duplex model for the Southern Uplands of Scotland. Journal of the Geological Society, London 144, 753–64.CrossRefGoogle Scholar
Stone, P., Green, P. M., Lintern, B. C., Simpson, P. R. and Plant, J. A. 1993. Regional geochemical variation across the Iapetus Suture Zone: tectonic implications. Scottish Journal of Geology 29, 113–21.CrossRefGoogle Scholar
Stone, P., Green, P. M. & Williams, T. M. 1997. Relationship of source and drainage geochemistry in the British paratectonic Caledonides: an exploratory regional assessment. Transactions of the Institution of Mining and Metallurgy 106, B79–B84.Google Scholar
Stone, P., Plant, J. A., Mendum, J. R. & Green, P. M. 1999. A regional geochemical assessment of some terrane relationships in the British Caledonides. Scottish Journal of Geology 35, 145–56.CrossRefGoogle Scholar
Stone, P. & Evans, J. A. 1995. Nd–isotope study of provenance patterns across the British sector of the Iapetus Suture. Geological Magazine 132, 571–80.CrossRefGoogle Scholar
Stone, P. & Evans, J. A. 2001. Silurian provenance variation in the Southern Uplands Terrane assessed using neodymium isotopes. Transactions of the Royal Society of Edinburgh: Earth Sciences, 91 (for 2000), 447–55.CrossRefGoogle Scholar
Styles, M.T., Perez-Alvarez, M. & Floyd, J. D. 1995. Pyroxenous greywackes in the Southern Uplands of Scotland and their petrotectonic implications. Geological Magazine 132, 539–17.CrossRefGoogle Scholar
Trench, A. & Torsvik, T. H. 1992. The closure of the Iapetus Ocean and Tornquist Sea: new palaeomagnetic constraints. Journal of the Geological Society, London 149, 867–70.CrossRefGoogle Scholar
Walton, E. K. 1955. Silurian greywackes in Peeblesshire. Proceedings of the Royal Society of Edinburgh Sect. B 65, 327–57.CrossRefGoogle Scholar
Walton, E. K. & Oliver, G. J. H. 1991. Chapter 6 Lower Palaeozoic-Stratigraphy. In Craig, G. Y. (ed.) Geology of Scotland, 161–93. London: The Geological Society.Google Scholar
White, D. E., Barron, H. F., Barnes, R. P. & Lintern, B. C. 1992 (for 1991). Biostratigraphy of late Llandovery (Telychian) and Wenlock turbiditic sequences in the SW Southern Uplands, Scotland. Transactions of the Royal Society of Edinburgh: Earth Sciences 82, 297–322.CrossRefGoogle Scholar
Wilson, T. H. 1931. The petrology of the Queensberry Grits in the Moffat (Dumfriesshire) districts (Unpublished M.Sc. Thesis, University of Leeds).Google Scholar