Loop Head - Ross Formation - Deepwater Sand Sheets with Low Relief Channel Incision

This page represents a gallery of photographs that illustrate the geology of the Ross Formation where it outcrops between the Atlantic shore and the north side of the Shannon Estuary in Co Clare.

The photographs in this gallery were taken by Christopher Kendall, Peter Haughton and David Pyles. We hope you enjoy the results of our collaboration. Our special thanks to David Pyles for his overview of the Loop Head cliffs above, taken from a helicopter and other shots referenced in the gallery. The height of these cliffs is around 45-50 m.

The gallery illustrates the character of the deepwater sediments of the Ross Formation at Loop Head. Here the Ross Formation section is represented by deepwater sheet sand fan lobes exhibiting sparse shallow channeling. Elliot (2000) records how these are the thicker bedded, high net-to-gross, amalgamated sheet turbidites of the lower part of the Ross Sandstone Formation turbidite system. Shaley partings occur between many of the sands and this may compartmentalize these sands, seperating them in terms of their potential reservoir quality from those above. Channeling may enhance vertical reservoir continuity between the stacked sheets, rendering them amalgamated?

At the Bridges of Ross exposure to the north, the fan lobes pass upward into a wide spread slump horizon. Note the neat monocline that desects the line of cliffs from north to south.

 

001-Loop-Head-Ross-Fm-Co-Clare 002-Loophead-Pyles-Heli 003-Loop-Head-South-Pyles 004-Loop-Head-NorthEast-Pyl 005-Loop-Head-Ross-Fm-Co-Clare
001 Loop Head 002 Loop Head 003 Loop Head South 004 Loop Head NE 005 Loop Head
006-Loop-Head-Ross-Fm-Co-Clare 007-Loop-Head-Ross-Fm-Co-Clare 008-Loop-Head-Ross-Fm-Co-Clare 009-Loop-Head-Ross-Fm-Co-Clare 010-Loop-Head-Ross-Fm-Co-Clare
006 Loop Head 007 Loop Head 008 Loop Head 009 Loop Head 010 Loop Head
011-Loop-Head-Ross-Fm-Co-Clare 012-Loop-Head-Ross-Fm-Co-Clare 013-Loop-Head-Ross-Fm-Co-Clare 014-Loop-Head-Ross-Fm-Co-Clare 015-Loop-Head-Ross-Fm-Co-Clare
011 Loop Head 012 Loop Head 013 Loop Head 014 Loop Head 015 Loop Head
016-Loop-Head-Ross-Fm-Co-Clare 017-Loop-Head-Ross-Fm-Co-Clare      
016 Loop Head 017 Loop Head

References

Chapin, M.A., Davies, P., Gibson, J.L. & Pettingill, H.S. (1994), Reservoir architecture of turbidite sheet sandstones in laterally extensive outcrops, Ross Formation, western Ireland. In Weimer, P., Bouma, A.H. & Perkins, R.F (eds), Submarine fans and turbidite systems, GCSSEPM Foundation 15th Annual Research Conference, 53 68.

Collinson, J.D., Martinsen, O. Bakken, B. and Kloster, A. (1991), Early fill of the western Irish Namurian Basin: a complex relationship between turbidites and deltas. Basin Research, 3, 223 242.

Davies, S.J. & Elliott, T. (1996), Spectral gamma ray characterisation of high resolution sequence stratigraphy: examples from Upper Carboniferous fluvio deltaic systems, Co. Clare, Ireland. In Howell, J.A. & Aitken, J.F. (eds) High resolution sequence stratigraphy: innovations and applications. Special Publication of the Geological Society London, 104, 25 35.

Elliott, T., 2000, Depositional architecture of a sand rich, channelized turbidite system: the Upper Carboniferous Ross Sandstone Formation, Western Ireland. in P. Weimer, R. M. Slatt, A. H. Bouma, and D. T. Lawrence, eds., Deep water reservoirs of the world: Gulf Coast Section SEPM Foundation, Twentieth Annual Research Conference, p. 342–373.

Elliott, T.Pulham, A.J., and Davies, S.J., 2000, Sedimentology, sequence stratigraphy and spectral gamma ray expression of turbidite, slope and deltaic depositional sytems in an Upper Carboniferous basin fill succession, western Ireland: Int. Ass. Sed. Conference, Dublin Ireland, Field Guide, p 1 40.

Gill, W.D. (1979), Syndepositional sliding and slumping in the West Clare Namurian Basin, Ireland. Geological Survey of Ireland Special Paper 4, 31pp.
.

Hodson, F., 1954a, The beds above the Carboniferous limestone in north west County Clare, Eire: Quarterly Journal of the Geological Society of London, v. 109, p. 259 283.

Hodson, F., 1954b, The Carboniferous rocks of Foynes Island, County Limerick: Geological Magazine, no. 2, p. 153 160.

Hodson, F. & Lewarne, G.C. (1961) A mid Carboniferous (Namurian) basin in parts of the counties of Limerick and Clare, Ireland. Quart. Geol. Soc. Lond., 117, 307 333.

Martinsen, O.J. (1989), Styles of soft sediment deformation on a Namurian (Carboniferous) delta slope, western Ireland Namurian Basin, Ireland. In Whatley, M.K.G. & Pickering, K.T. (eds) Deltas: sites and traps for fossil fuels, Geological Society Special Publication, 41, 167 177.

Martinsen, O.J. & Bakken, B. (1990), Extensional and compressional zones in slumps and slides in the Namurian of County Clare, Ireland. Journal of the Geological Society, 147, 153 164.

Pulham, A.J. (1987), Depositional and syn sedimentary deformation processes in Namurian deltaic sequences of west County Clare, Ireland. Unpublished PhD thesis, University of Wales, Swansea.

Pulham, A.J. (1989), Controls on internal structure and architecture of sandstone bodies within Upper carboniferous fluvial dominated deltas, County Clare, western Ireland. In Whatley, M.K.G. & Pickering, K.T. (eds) Deltas: sites and traps for fossil fuels, Geological Society Special Publication, 41, 179 203.

Pyles, D.R. (in press), Stratigraphic architecture of a structually confined submarine fan, Carboniferous Ross Sandstone, Western Ireland, Bulletin of the American Association of Petroleum Geologists.

Rider, M.H. (1969), Sedimentological studies in the West Clare Namurian Basin, Ireland and the Mississippi Delta. Unpublished PhD thesis, Imperial College London.

Rider, M.H. (1974), The Namurian of West County Clare. Proceedings of the Royal Irish Academy, 74B, 125 142.

Rider, M.H. (1978), Growth faults in the Carboniferous of western Ireland. Bulletin of the American Association of Petroleum Geologists, 62, 2191 2213.

Sevastopulo, G.D. (1981), Upper Carboniferous. In Holland, C.H. (ed.) A geology of Ireland. Scottish Academic Press, 173 199.

Wignall, P.B. and Best, J.L. (2000), The Western Irish Namurian Basin reassessed. Basin Research 12, 59 78.

Wignall, P.B. and Best, J.L. (2002), The Western Irish Namurian Basin reassessed – a discussion. Basin Research 14, 523 542.
home | about site | site contents | site map| submit a site | contact us | top
Copyright © 2005 University of South Carolina - Geology Department All Rights Reserved
Last Revised: January 13, 2008