Precambrian rocks in Anglesey, southwest Llŷn and southeast Ireland
W. Gibbons, D. Tietzsch-Tyler, J. M. Horák, F. C. Murphy, 1994. "Precambrian rocks in Anglesey, southwest Llŷn and southeast Ireland", A revised correlation of Pre-Cambrian rocks in the British Isles, W. Gibbons, A. L. Harris
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This chapter deals with the oldest rocks that crop out at opposite ends of a narrow belt running southwest from the island of Anglesey in North Wales across the Irish Sea to the southeasternmost corner of Ireland. Between these two outcrop areas, exposures similar to some of those in Anglesey are found on the Welsh mainland along the southwestern margin of the Llŷn Peninsula (Fig. 24). In Wales, since the work of Blake (1888), Greenly (1919) and Matley (1928), these rocks have been referred to as Monian. In Ireland, following work by Baker (1955, 1969, 1970), the exposures have been placed within either the Rosslare Complex or the Cullenstown Formation. Although many previous publications have assumed a Precambrian age for all of these rocks, it is likely that they include some Cambrian rocks. In particular, the sediments that comprise the Cullenstown Formation, correlated with Monian sediments exposed in western Anglesey, are now interpreted as Cambrian (Tietzsch-Tyler & Phillips 1989; Bennett et al. 1989). Nevertheless, given the uncertainty that exists over both the absolute age of many rocks in these areas, and of the Precambrian-Cambrian boundary in general, all Monian and Rosslare/Cullenstown exposures have been included in this rewritten Special Report.
Figures & Tables
This second and completely revised edition of Special Report No. 6 provides a comprehensive review and report of work earned out since 1975. It emphasizes the relationship between, and the correlation of, the units in to which the Precambrian rocks of England, Ireland, Scotland, Wales and the Channel Islands have been divided The chapters also provide a comprehensive bibliography of the work on which the correlations have been based.