Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-22T06:29:53.290Z Has data issue: false hasContentIssue false

Sedimentation and palaeogeographical significance of the Silurian rocks of the Louisburgh–Clare Island succession, western Ireland

Published online by Cambridge University Press:  03 November 2011

C. Kelly Maguire
Affiliation:
Geochem Group Ltd., Chester Street, Chester, CH4 8RD, UK
John R. Graham
Affiliation:
Department of Geology, Trinity College Dublin, Dublin 2, Ireland

Abstract

There are three distinct Silurian successions exposed in South Mayo and North Galway, western Ireland, of which the Louisburgh-Clare Island succession is the most northerly. It is separated from the adjacent Croagh Patrick succession by the Emlagh Fault. Three of the formations (Strake Banded, Knockmore Sandstone, Bunnamohaun Siltstone) in this 1·5 km Louisburgh–Clare Island succession had previously been interpreted as intertidal to offshore marine deposits. Almost all the facies present display characteristics of fluvial sedimentation and there is evidence for a contemporaneous volcanic centre to the west of the present outcrop. The exceptions are some grey laminated mudrocks with a fragmentary fauna which are interpreted as lacustrine and which show striking similarities to parts of the Silurian inliers in the central Midland Valley of Scotland. Despite these similarities the evidence for direct connection between western Ireland and Scotland is unproven. Within western Ireland correlations are hindered by uncertainties of the age of the Louisburgh-Clare Island succession and the age span of the adjacent Croagh Patrick succession.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1995

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

Aherne, S., Reynolds, N. A. & Burke, D. J. 1992. Gold mineralisation in the Silurian and Ordovician of south Mayo. In Bowden, A. A., Earls, G., O'Connor, P. G. & Pyne, J. (eds) The Irish minerals industry 1980-1990. 3949. Dublin: Irish Association Economic Geology.Google Scholar
Ashley, G. 1990. Classification of large scale subaqueous bedforms: a new look at an old problem. SEDIMENT PETROL 60, 160–72.Google Scholar
Bickle, M. J.Kidd, R. G. W. & Nisbet, E. 1972. The Silurian of the Croagh Patrick Range, Co. Mayo. SCI PROC R DUBLIN SOC 4A, 231–49. Bath: The Geological Society.Google Scholar
Bray, A. A. 1985. The evolution of the terrestrial vertebrates: environmental and physiological considerations. PHIL TRANS R SOC LONDON B309, 243–58.Google Scholar
Cotter, E. & Graham, J. R. 1991. Coastal plain sedimentation in the late Devonian of southern Ireland: hummocky cross-stratification in fluvial deposits? SEDIMENT GEOL 72, 201–24.Google Scholar
Dewey, J. F. & Ryan, P. D. 1990. The Ordovician evolution of the South Mayo Trough, western Ireland. TECTONICS 9, 887901.CrossRefGoogle Scholar
Gilmore, B. 1992. Scroll coprolites from the Silurian of Ireland and the feeding of early vertebrates. PALAEONTOLOGY 35, 319–33.Google Scholar
Graham, J. R., Leake, B. E. & Ryan, P. D. 1989. The geology of South Mayo. Edinburgh: Scottish Academic Press.Google Scholar
Halstead, L. B. 1985. The vertebrate invasion of fresh water. PHIL TRANS R SOC LONDON B309, 243–58.Google Scholar
Hamilton, R. F. M. & Trewin, N. H. 1988. Environmental controls on fish faunas of the Middle Devonian Orcadian Basin. In McMillan, N. J., Embry, A. F. & Glass, D. J. (eds) Devonian of the World. 589600, CAN SOC PETROL GEOL MEM 14, vol. 3.Google Scholar
Harms, J. C.Southard, J. B. & Walker, R. G. 1982. Structures and sequences in clastic rocks. SEPM SHORT COURSE 9.Google Scholar
Johnston, J. D. & Phillips, W. E. A. (1995). Terrane amalgamation in the Clew Bay region, west of Ireland. GEOL MAG 132, 485501.Google Scholar
Kelly, T. J. & Max, M. D. 1979. The geology of the northern part of the Murrisk Trough. PROC R IRISH ACAD 79B, 191206.Google Scholar
Kinahan, G. H., Wilkinson, S. B., Nolan, J. & Leonard, H. 1876. Memoir Geological Survey Ireland. Sheets 83 and 84.Google Scholar
Laird, M. G. 1969. Sedimentation studies in the Silurian rocks of NW Galway, Eire. PhD thesis, University of Oxford.Google Scholar
Maguire, C. K. 1989. The sedimentology and stratigraphy of the Silurian succession of Louisburgh and Clare Island, County Mayo. Western Ireland. PhD thesis, University of Dublin.Google Scholar
Marshall, J. E. A. 1991. Palynology of the Stonehaven Group, Scotland: evidence for a mid-Silurian age and its geological implications. GEOL MAG 128, 283–6.CrossRefGoogle Scholar
Max, M. D. 1989. The Clew Bay Group: A displaced terrane of Highland Border rocks (Cambro-Ordovician) in northwest Ireland. GEOL J 24, 117.CrossRefGoogle Scholar
Menuge, J. F., Williams, D. M. & O'Connor, P. D. 1995. Silurian turbidites used to reconstruct a volcanic terrain and its Mesoproterozoic basement in the Irish Caledonides. J GEOL SOC LONDON 152, 269–78.CrossRefGoogle Scholar
Palmer, D., Johnston, J. D., Dooley, T. & Maguire, K. 1989. The Silurian of Clew Bay, Ireland: part of the Midland Valley of Scotland? J GEOL SOC LONDON 146, 385–8.Google Scholar
Phillips, W. E. A. 1966. The geology of Clare Island, County Mayo, Ireland. PhD thesis, University of Dublin.Google Scholar
Phillips, W. E. A. 1974. The stratigraphy, sedimentary environments and palaeogeography of the Silurian strata of Clare Island, Co. Mayo, Ireland. J GEOL SOC LONDON 130, 1941.Google Scholar
Phillips, W. E. A. 1983. The geology of northern Murrisk. In Archer, J. B. & Ryan, P. D. (eds) Geological guide to the Caledonides of western Ireland. Geological Survey of Ireland Guide Series 4, 3742.Google Scholar
Phillips, W. E. A., Rickards, R. B. & Dewey, J. F. 1970. The Lower Palaeozoic rocks of the Louisburgh area, Co. Mayo. PROC R IRISH ACAD 70B, 195209.Google Scholar
Smethurst, M. A., MacNiocaill, C. & Ryan, P. D. 1994. Oroclinal bending in the Caledonides of western Ireland. J GEOL SOC LONDON 151, 315–28.CrossRefGoogle Scholar
Smith, D. G. 1979. The distribution of trilete spores in Irish Silurian rocks. In Harris, A. L., Holland, C. H. & Leake, B. E. (eds) The Caledonides of the British Isles reviewed, 423–32. Edinburgh: Scottish Academic Press.Google Scholar
Soper, N. J. & Woodcock, N. H. 1990. Silurian collision and sediment dispersal patterns in southern Britain. GEOL MAG 127, 527–42.Google Scholar
Thompson, K. S. 1980. The ecology of Devonian lobe-finned fishes. In Panchen, A. L. (ed.) The terrestrial environment and the origin of land vertebrates, 110. London: Academic Press.Google Scholar
Thompson, S. J., Shine, C. H., Cooper, C., Halls, C. & Zhao, R. 1992. Shear-hosted gold mineralisation in Co. Mayo, Ireland. In Bowden, A. A., Earls, G., O'Connor, P. G. & Pyne, J. (eds) The Irish minerals industry 1980-1990, 2138. Dublin: Irish Association Economic Geology.Google Scholar
Trewin, N. H. 1986. Palaeoecology and sedimentology of the Achanarras fish bed of the Middle Old Red Sandstone, Scotland. TRANS R SOC EDINBURGH: EARTH SCI 77, 2146.Google Scholar
Walker, R. G. 1963. Distinctive types of ripple drift cross lamination. SEDIMENTOLOGY 2, 173–88.Google Scholar
Walton, E. K. & Oliver, G. H. 1991. Lower Palaeozoic. In Craig, G. Y. (ed.) Geology of Scotland, 3rd edn, 161–94. Bath: The Geological Society.Google Scholar
Wellman, C. H. & Richardson, J. B. 1993. Terrestrial plant microfossils from Silurian inliers of the Midland Valley of Scotland. PALAEONTOLOGY 36, 155–93.Google Scholar
Williams, D. M. & Harper, D. A. T. 1988. A basin model for the Silurian of the Midland Valley of Scotland and Ireland. J GEOL SOC LONDON 145, 741–8.Google Scholar
Williams, D. M. & Harper, D. A. T. 1991. End-Silurian modifications of Ordovician terranes in western Ireland. J GEOL SOC LONDON 148, 165–71.Google Scholar
Williams, D. M., O'Connor, P. D. & Menuge, J. 1992. Silurian turbidite provenance and the closure of lapetus. J GEOL SOC LONDON 149, 349–57.Google Scholar
Williams, D. M., Harkin, J., Armstrong, H. A. & Higgs, K. T. 1994. A late Caledonian melange in Ireland: implications for tectonic models. J GEOL SOC LONDON 151, 307–14.Google Scholar