Facies change in upper devonian and lower carboniferous rocks of Southern Ireland

Abstract

In south-west Ireland 8, OOO ft (2,440 m) of marine sandstones and mudstones, the Cork Beds (?Upper Famennian to E Zone, Carboniferous, in age), overlie the Old Red Sandstone. Farther north the Old Red Sandstone is succeeded by thin Lower Limestone Shales overlain by thick Waulsortian bank limestones.A critical section (North Ringabella) west of Cork Harbour, in which 6,500 ft (1,981 m) of Old Red Sandstone and Cork Beds is exposed, is described and divided into ten formations.

Facies relationships in the Upper Devonian‐Lower Carboniferous of southwest Ireland and adjacent regions

“…A summary of the stratigraphic schemes proposed by the authors detailed above is given in Table 1. Naylor (1966) established a four-fold subdivision of the Cork Beds sequence on the Old Head of Kinsale (Fig. 1, Column 4).…”

“…For this reason, therefore, we prefer to use the lithostratigraphic terminology established in Naylor (1966and 1969) and Naylor et al (1969, except that we propose to reduce all the groups and formations defined in those papers to formation and member rank respectively. There is general agreement between workers in the area that the original stratigraphic units were placed one rank too high in the hierarchy of stratigraphic terms.…”

“…The depositional environments of the Cork Facies in South Cork have been discussed at some length by several authors (Naylor 1966(Naylor , 1969Kuijpers 1971 a andb, 1972;de Raaf 1970). The West Cork sequences were discussed in Coe and Selwood (1968), Naylor et 01.…”

“…The sediments of the Kinsale Formation were deposited in the main in relatively shallow marine conditions. Naylor (1966) concluded that the balance of evidence suggested a delta-front platform or proximal prodelta slope environment for the sandier and laminated rocks, and a distal pro-delta slope or prodelta shelf environment for the uniform mudstones. De Raaf (1970) (Naylor 1966).…”

“…There is general agreement in broad terms that the succession above the Old Red Sandstone of thin 'Lower Limestone Shales' (Tournaisian) overlain by thick bank and shelf limestones (TournaisianVistan) north of a line from Cork to Kenmare passes southwards across the Cork Harbour-Kenmare line by facies change into a thick, dominantly marine, sandstonesiltstone-mudstone sequence of Famennian to early Namurian age-the Cork Beds (Naylor 1966). Much detailed work, however, is still required to elucidate the details of the transition.…”