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The Wenlock sediments of north-west Galway, Ireland.

Published online by Cambridge University Press:  01 May 2009

M. G. Laird  and
W. S. McKerrow
M. G. Laird
Affiliation:
New Zealand Geological Survey, P.O. Box 90, Greymouth, New Zealand
W. S. McKerrow
Affiliation:
Dept. of Geology and Mineralogy, University of Oxford, Parks Road, Oxford
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Summary

This work describes the Wenlock sedimentary sequences south of Killary Harbour where the fullest successions in north-west Galway are exposed; much of the Upper Silurian in the east (Joyces Country) has been removed by erosion.

The Wenlock beds (the Upper Owenduff and Killary Harbour Groups) rest on shallow marine and continental sediments (the Lower Owenduff Group) of Upper Llandovery (C5–6) age. Conglomerates near the base of the Wenlock are followed by 1,500 m of sandstones, which are mostly turbidites and which contain Middle Wenlock graptolites. These basin deposits are succeeded by a transitional sequence of rise, slope and shelf clastics, also of Middle Wenlock age. The youngest Silurian beds exposed are 800 m of red lagoonal deposits with Lingula.

During Wenlock times, the sediment supply to north-west Galway was mainly from the north and north-west. This observation fits well with the regional picture which places Galway near the north-west margin of a Silurian basin which extended eastwards across Ireland.

Type
Articles
Information
Geological Magazine , Volume 107 , Issue 4 , July 1970 , pp. 297 - 317
Copyright
Copyright © Cambridge University Press 1970

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References

REFERENCES

Cummins, W. A., 1969. Patterns of sedimentation in the Silurian rocks of Wales. pp. 219–237, in Wood, A. (Ed.): The Pre-Cambrian and Lower Palaeozoic rocks of Wales. University of Wales Press, Cardiff.Google Scholar
Dewey, J. F., 1962. The provenance and emplacement of Upper Arenigian turbidites in Co. Mayo, Eire. Geol. Mag. 99, 238–252.CrossRefGoogle Scholar
1963. The Lower Palaeozoic stratigraphy of central Murrisk, Co. Mayo, Ireland, and the evolution of the South Mayo Trough. Q. Jl geol. Soc. Lond. 119, 313–344.CrossRefGoogle Scholar
1969. Evolution of the Appalachian/Caledonian Orogen. Nature, Lond., 222, 124–9.CrossRefGoogle Scholar
McKerrow, W. S. & Moorbath, S., 1970. The relationship between isotopic ages, uplift and sedimentation during Ordovician times in western Ireland. Scott.J. Geol. 6 (Pt. 2), 133–145.Google Scholar
Holland, C. H., 1969. The Welsh Silurian geosyncline in its regional context. pp. 203–217, in Wood, A. (Ed.): The Pre-Cambrian and Lower Palaeozoic rocks of Wales. University of Wales Press, Cardiff.Google Scholar
Laird, M. G. 1968. Rotational slumps and slump scars in Silurian rocks, western Ireland. Sedimentology, 10, 111–120.CrossRefGoogle Scholar
McBride, E. F., 1962. Flysch and associated beds of the Martinsburg Formation (Ordovician), Central Appalachians. J. sedim. Petrol, 32, 39–91.Google Scholar
McKerrow, W. S., 1969. The Silurian rocks of Ireland and a comparison with Newfoundland. In Kay, M. (Ed.): Proceedings of the Gander Conference, 1967.CrossRefGoogle Scholar
McKerrow, W. S. & Campbell, C. J., 1960. The stratigraphy and structure of the Lower Palaeozoic rocks of north-west Galway. Scient. Proc. R. Dubl. Soc., A, 1, 27–52.Google Scholar
McManus, J., 1967. Sedimentology of the Partry Series in the Partry Mountains, Co. Mayo, Eire. Geol. Mag., 104, 585–607.CrossRefGoogle Scholar
Moorbath, S., Bell, K., Leake, B. E., & McKerrow, W. S., 1968. Geochronological studies in Connemara and Murrisk, western Ireland. pp. 259–298, in Hamilton, E. I. & Farquhar, R. M. (Eds.): Radiometric dating for geologists. London.Google Scholar
Piper, D. J. W., 1967. A new interpretation of the Llandovery sequence of north Connemara, Eire. Geol. Mag., 104, 253–267.CrossRefGoogle Scholar
1969. Geosyncline margin sediments in the Silurian of west Connacht, Eire, in Kay, M. (Ed.): Proceedings of the Gander Conference, 1967.Google Scholar
Rickards, R. B. & Smith, W. R., 1968. The Silurian graptolites of Mayo and Galway. Scient. Proc. R. Dubl. Soc., A. 3, 129–135.Google Scholar
Unrug, R., 1963. Istebna Beds – a fluxoturbidity formation in the Carpathian flysch. Roczn. pol. Tow. geol., 33, 49–92.Google Scholar
Williams, E. G., Turner, F. J., & Gilbert, C. M., 1955. Petrography. San Francisco. 406 pp.Google Scholar
Ziegler, A. M., 1966. The Silurian brachiopod Eocoelia hemisphaerica (J. de C. Sowerby) and related species. Palaeontology, 9, 523–43.Google Scholar
Ziegler, A. M., Cocks, L. R. M., & Bambach, R. K., 1968. The composition and structure of Lower Silurian marine communities. Lethaia, Oslo, 1, 1–27.CrossRefGoogle Scholar
Ziegler, A. M., Cocks, L. R. M. & McKerrow, W. S. 1968. The Llandovery transgression of the Welsh Borderland. Palaeontology, 11, 736–82.Google Scholar