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Lithostratigraphy of the Ordovician rocks in the Southern Uplands: Crawford Group, Moffat Shale Group, Leadhills Supergroup

  • J. D. Floyd (a1)

Abstract

A formal lithostratigraphy is erected for all the Ordovician rocks in the Southern Uplands of Scotland. At the base of the succession, the Crawford Group (Arenig–Llanvirn) encompasses the chert and lava sequences usually associated with the tract-bounding faults, and includes the only proven Arenig rocks in the Southern Uplands. The overlying Moffat Shale Group (Caradoc–Llandovery) is now restricted to the black and grey graptolitic shales which succeed the grey and red chert successions. The Leadhills Supergroup (Caradoc–Ashgill) forms the overwhelming bulk of the sedimentary succession and includes the thick Ordovician turbidite successions of the Northern Belt. Existing stratigraphical terminology is reviewed, revised or extended as appropriate to maintain maximum continuity with current usage. Type sections for each unit are either proposed, where newly defined or revised, or cited in the case of existing definitions.

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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. TRANS R SOC EDINBURGH: EARTH SCI 77, 203–22.
Anderson, T. B. & Oliver, G. J. H. 1987. Reply to “Constraints on the significance of the Orlock Bridge Faultwithin the Scottish Southern Uplands”, a discussion of “The Orlock Bridge Fault: a major Late Caledonian sinistral fault in the Southern Uplands terrane, British Isles”. TRANS R SOC EDINBURGH: EARTH SCI 78, 223–5.
Armstrong, H. A., Clarkson, E. N. K. & Owen, A. W. 1990. A new Lower Ordovician conodont faunule from the Northern Belt of the Southern Uplands. SCOTT J GEOL 26, 4752.
Armstrong, H. A., Owen, A. W., Scrutton, C. T., Clarkson, E. N. K. & Taylor, C. M. (in press) Palaeontological constraints on the evolution of the Northern Belt, SouthernUplands–implications for the Southern Uplands controversy. J GEOL SOC LONDON.
Barrett, T. J., Jenkyns, H. C, Leggett, J. K. & Robertson, A. H. F. 1982. Comment on ‘Age and origin of Ballantrae ophiolite and its significance to the Caledonian orogeny and the Ordovician time scale’. GEOLOGY 10, 331.
Batchelor, R. A. & Weir, J. A. 1988. Metabentonite geochemistry: magmatic cycles and graptolite extinctions at Dob's Linn, southern Scotland. TRANS R SOC EDINBURGH: EARTH SCI 79, 1941.
British Geological Survey 1992. The Rhins of Galloway. Scotland, Sheets 1 and 3 withparts of 7 and 4W. SolidGeology. 1:50 000. Keyworth, Nottingham: British Geological Survey.
British Geological Survey 1993. Regional geochemistry of southern Scotland and part of northern England. Keyworth, Nottingham: British Geological Survey.
British Geological Survey 1994a. Carrick. Scotland Sheet 8W. Solid Geology. 1:50000. Keyworth, Nottingham: British Geological Survey.
British Geological Survey 1994b. Loch Doon. Scotland Sheet 8E. Solid Geology. 1:50 000. Keyworth, Nottingham, British Geological Survey.
Cameron, I. B., Stone, P. & Smellie, J. 1986. Geology of the country around Girvan. Explanation of 1:50 000 Scotland Sheet 7. London: HMSO for British Geological Survey.
Casey, D. M. 1983. Geological studies in the Central Belt of the Eastern Southern Uplands of Scotland. University of Oxford PhD thesis (unpubl.).
Clarkson, E. N. K., Harper, D. A. T., Owen, A. W. & Taylor, C. M. 1992. Ordovician faunas in mass-flow deposits, Southern Scotland. TERRA NOVA 4, 245–53.
Craig, G. Y. & Walton, E. K. 1959. Sequence and structure in the Silurian rocks in Kirkcudbrightshire. GEOL MAG 96, 209–20.
Duller, P. R. & Floyd, J. D. 1995. Turbidite geochemistry and provenance studies in the Southern Uplands of Scotland. GEOL MAG 132, 557–69.
Elders, C. F. 1987. The provenance of granite boulders in conglomerates of the Northern and Central Belts of the Southern Uplands of Scotland. J GEOL SOC LONDON 144, 853–63.
Evans, J. A., Stone, P. & Floyd, J. D. 1991. Isotopic characteristics of Ordovician greywacke provenance in the Southern Uplands of Scotland. In Morton, A. C, Todd, S. P. & Haughton, P. D. W. (eds) Developments in sedimentary provenance studies, 161–72. GEOL SOC LONDON SPEC PUBL 57.
Finney, S. C. & Bergstrom, S. M. 1986. Biostratigraphy of the Ordovician Nemagraptus gracilis Zone. In Hughes, C. P. & Rickards, R. B. (eds) Palaeoecology andbiostratigraphy of graptolites, 4759. GEOL SOC LONDON SPEC PUBL 20.
Floyd, J. D. 1976. The Ordovician rocks of West Nithsdale. University of St Andrews, PhD thesis (unpubl.).
Floyd, J. D. 1982. Stratigraphy of a flysch succession: the Ordovician of W Nithsdale, SW Scotland. TRANS R SOC EDINBURGH: EARTH SCI 73, 19.
Floyd, J. D. 1994. The derivation and definition of the ‘Southern Upland Fault’: a review of the Midland Valley-Southern Uplands terrane boundary. SCOTT J GEOL 30, 5162.
Floyd, J. D. (in press). Geology of the Carrick-Loch Doon district. Sheets 8W and 8E (Scotland). MEM BR GEOL SURV.
Floyd, J. D. & Kimbell, G. S. 1995. Magnetic and tectonostratigraphic correlation at a terrane boundary: the Tappins Group of the Southern Uplands. GEOL MAG 132, 515–21.
Floyd, J. D. & Rushton, A. W. A. 1993. Ashgill greywackes in the Southern Uplands of Scotland: an extension of the Ordovician succession in the Northern Belt. TRANS R SOC EDINBURGH: EARTH SCI 84, 7985.
Floyd, J. D. & Stone, P. 1992. Tweedsmuir. In McAdam, A. D., Clarkson, E. N. K. & Stone, P. (eds) Scottish Borders geology. An excursion guide, 147–58. Edinburgh: Scottish Academic Press.
Floyd, J. D. & Trench, A. 1989. Magnetic susceptibility contrasts in Ordovician greywackes of the Southern Uplands of Scotland. J GEOL SOC LONDON 146, 7783.
Floyd, J. D., Stone, P., Barnes, R. P. & Lintern, B. C. 1987.Constraints on the significance of the Orlock Bridge Fault within the Scottish Southern Uplands, a discussion of “The Orlock Bridge Fault: a major Late Caledonian sinistral fault in the Southern Uplands terrane, British Isles”. TRANS R SOC EDINBURGH: EARTH SCI 78, 219–21.
Geikie, A. 1871. Explanation of Sheet 15. Parts of Dumfriesshire, Lanarkshire and Ayrshire. MEM GEOL SURV SCOTLAND.
Hepworth, B. C. 1981. Geology of the rocks between Leadhills and Abington, Lanarkshire. University of St Andrews PhD thesis (unpubl.).
Hepworth, B. C, Oliver, G. J. H. & McMurtry, M. J., 1982. Sedimentology, volcanism, structure and metamorphism of the northern margin of a Lower Palaeozoic accretionary complex: Bail Hill-Abington area of the Southern Uplands of Scotland. In Leggett, J. K. (ed) Trench-forearc geology: Sedimentation and tectonics on modern andancient active plate margins, 521–34. GEOL SOC LONDON SPEC PUBL 10.
Holroyd, J. 1978. The sedimentological and geotectonic significance of Lower Palaeozoic flysch rudites. University of Wales PhD thesis (unpubl.).
Hughes, R. A. & Boland, M. 1995. The Ordovician and Silurian rocks of ScottishSheet 24E (Peebles). BR GEOL SURV TECH REP WA/95/14.
Ince, D. 1984. Sedimentation and tectonism in the Middle Ordovician of the Girvan district, SW Scotland. TRANS R SOC EDINBURGH: EARTH. SCI 75, 225–37.
Kassi, A. M. 1984. Lower Palaeozoic geology of the Gala area, Borders Region, Scotland. University of St Andrews PhD thesis (unpubl.).
Kassi, A. M. & Weir, J. A. 1993. Depositional and geotectonic history of the Gala area, eastern Southern Uplands, Scotland. TRANS R SOC EDINBURGH: EARTH SCI 84, 161–73.
Kelling, G. 1958. The Ordovician rocks of the Rhinns of Galloway. University ofEdinburgh, PhD thesis (unpubl.).
Kelling, G. 1961. The stratigraphy and structure of the Ordovician rocks of the Rhinnsof Galloway. Q J GEOL SOC LONDON 117, 3775.
Kelling, G. 1962. The petrology and sedimentation of Upper Ordovician rocks in the Rhins of Galloway, south-west Scotland. TRANS R SOC EDINBURGH: EARTH SCI 65, 107–37.
Kelling, G. & Welsh, W. 1970. The Loch Ryan fault. SCOTT J GEOL 6, 266–71.
Lamont, A. 1975. Noble House, Lamancha. In Craig, G. Y. & Duff, P.McL, D. (eds) The geology of the Lothians and south east Scotland. An excursion guide, 158–66. Edinburgh: Scottish Academic Press.
Lamont, A. & Lindstrom, M. 1957. Arenigian and Llandeilian cherts identified in the Southern Uplands by means of conodonts, etc. TRANS EDINBURGH GEOL SOC 17, 6070.
Lapworth, C. 1878. The Moffat Series. Q J GEOL SOC LONDON 34, 240346.
Leggett, J. K. 1978. Studies in the Ordovician rocks of the Southern Uplands, with particular reference to the Northern Belt. University of Oxford, DPhil thesis (unpubl.).
Leggett, J. K. 1980a. The sedimentological evolution of a Lower Palaeozoic accretionary fore-arc in the Southern Uplands of Scotland. SEDIMENTOLOGY 27, 401–17.
Leggett, J. K. 1980b. Palaeogeographic setting of the Wrae Limestone: an Ordovician submarine-slide deposit in Tweeddale. SCOTT J GEOL 16, 91104.
Leggett, J. K., McKerrow, W. S. & Eales, M. H. 1979. The Southern Uplands of Scotland: a Lower Palaeozoic accretionary prism. J GEOL SOC LONDON 136, 755–70.
McKerrow, W. S., Leggett, J. K. & Eales, M. H. 1977. Imbricate thrust model of the Southern Uplands of Scotland. NATURE, LONDON 267, 237–9.
McMurtry, M. J. 1980. The Ordovician rocks of the Bail Hill area, Sanquhar, South Scotland: Volcanism and sedimentation in the Iapetus Ocean. University of St Andrews, PhD thesis (unpubl.).
Merriman, R. J. & Roberts, B. 1990. Metabentonites in the Moffat Shale Group, Southern Uplands of Scotland: geochemical evidence of ensialic, marginal basin volcanism. GEOL MAG 127, 259–71.
Owen, A. W. & Clarkson, E. N. K. 1992. Trilobites from Kilbucho and Wallace's Cast and the location of the Northern Belt of the Southern Uplands during the late Ordovician. SCOT J GEOL 28, 317.
Peach, B. N. & Horne, J. 1899. The Silurian Rocks of Britain, Volume 1. Scotland. MEM GEOL SURV UK.
Phillips, E. R., Barnes, R. P., Merriman, R. J. & Floyd, J. D. 1995. The tectonic significance of Ordovician basic igneous rocks in the Southern Uplands, SW Scotland. GEOL MAG 132, 549–56.
Rushton, A. W. A. & Stone, P. 1991. Terrigenous input to the Moffat Shale sequence, Southern Uplands. SCOT J GEOL 27, 167–9.
Rushton, A. W. A. & Tunnicliff, S. P. 1996. Graptolites: Ordovician and Silurian biostratigraphy. In Stone, P. (ed.) Geology in southwest Scotland: an excursion guide. Keyworth: British Geological Survey.
Stone, P. 1995. Geology of the Rhins of Galloway district. Sheets 1 & 3, Scotland. MEM BR GEOL SURV.
Stone, P., Floyd, J. D., Barnes, R. P. & Lintern, B. C. 1987. A sequential back-arc and foreland basin thrustduplex model for the Southern Uplands of Scotland. J GEOL SOC LONDON 144, 753–64.
Styles, M. T., Perez-Alvarez, M. & Floyd, J. D. 1995. Pyroxenous greywackes in the Southern Uplands and theirpetrotectonic implications. GEOL MAG 132, 539–47.
Styles, M. T., Stone, P. & Floyd, J. D. 1989. Arc detritus in the Southern Uplands: mineralogical characterisation of a ‘missing’ terrane. J GEOL SOC LONDON 146, 397400.
Thirlwall, M. F. 1981. Peralkaline rhyolites from the Ordovician Tweeddale Lavas, Peeblesshire, Scotland. GEOL J 16, 41–4.
Thirlwall, M. F. & Bluck, B. J. 1984. Sr-Nd isotope and geological 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.
Toghill, P. 1970. Highest Ordovician (Hartfell Shales) graptolitic faunas from the Moffat area, south-west Scotland. BULL BR MUS NAT HIST GEOL 19, 126.
Walton, E. K. 1955. Silurian greywackes in Peeblesshire. PROC R SOC EDINBURGH B65, 327–57.
Walton, E. K. 1956. Two Ordovician conglomerates in south Ayrshire. TRANS GEOL SOC GLASGOW 22, 133–56.
Walton, E. K. & Oliver, G. J. H. 1991. Lower Palaeozoic-Stratigraphy.In Craig, G. Y. (ed.) Geology of Scotland (3rd edn). London: The Geological Society.
Webb, B., Rushton, A. W. A. & White, D. E. 1993. Mqffatdale and the upper Ettrick Valley: a description of the solid geology of parts of 1:25000 sheets NT 10, 11, 20 and 21. Classical areas of British Geology. London: HMSO for British Geological Survey.
Welsh, W. 1964. The Ordovician rocks of north-west Wigtownshire. University of Edinburgh, PhD thesis (unpubl.).
Williams, S. H. 1980. An Excursion Guide to Dob's Linn. PROC GEOL SOC GLASGOW, 121/122, 13-18.
Williams, S. H. 1982a. Upper Ordovician graptolites from the top Lower Hartfell Shale Formation (D. clingani and P. Hnearis Zones) near Moffat, southern Scotland. TRANS R SOC EDINBURGH: EARTH SCI 72, 229–55.
Williams, S. H. 1982b. The Late Ordovician graptolitic fauna of the Anceps Bands at Dob's Linn, southern Scotland. GEOLOGICA ET PALAEONTOLOGICA 16, 2956.
Williams, S. H. 1983. The Ordovician-Silurian boundary graptolite fauna of Dob's Linn, Southern Scotland. PALAEONTOLOGY 26, 605–39.
Williams, S. H. 1986. Top Ordovician and lowest Silurian of Dob's Linn. In Hughes, C. P. & Rickards, R. B. (eds) Palaeoecology and hiostratigraphy of graptolites. GEOL SOC LONDON SPEC PUBL 20, 165–71.
Williams, S. H. 1987. Upper Ordovician graptolites from the D. complanatus Zone of theMoffat and Girvan districts and their significance for correlation. SCOTT J GEOL 23, 6592.
Williams, S. H. 1994. Revision and definition of the C. wilsoni Zone (middle Ordovician) of southern Scotland. TRANS R SOC EDINBURGH: EARTH SCI 85, 143157.
Zalasiewicz, J. A., Rushton, A. W. A. & Owen, A. W. 1995. Late Caradoc graptolite faunal gradients across th Iapetus Ocean. GEOL MAG 132, 611–18.

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Lithostratigraphy of the Ordovician rocks in the Southern Uplands: Crawford Group, Moffat Shale Group, Leadhills Supergroup

  • J. D. Floyd (a1)

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