The Carboniferous Rocks at Loughshinny (County Dublin).

Abstract

1. Introduction [C.A.M.]. Loughshinny, a tiny fishing-village on the coast of County Dublin, about midway between the larger villages of Rush and Skerries, is well known to Dublin geologists for the fine exposures of contorted strata exhibited in the neighbouring cliffs. These exposures form part of an extensive coast-section of Carboniferous rocks which may be followed, with a few interruptions, for about 5 miles from Rush on the south to Skerries on the north. A description of the rocks in the southern portion of this coast section, from Rush as far north as a small cove called Brook's End, was given by us in 1905, together with an account of the faunal succession and correlation of the beds. The present paper continues the description northward from Brook's End, and is intended to be read in conjunction with our previous paper. The references given to former literature and maps in that paper apply equally to the ground now to be described. Before, however, describing in some detail the rocks around Loughshinny, it seems desirable to recapitulate very briefly the sequence of the rocks in the Rush portion of the coast-section. At Rush the lowest beds are a thick mass of dark slates (Rush Slates), with intercalated limestone-bands; they pass up into the Rush Conglomerates, and the latter into a calcareous group (Supra-Conglomerate Limestones and Carlyan Limestones). The ascending succession is as a whole from south to north, and the beds mentioned appeared, from the palæontological evidence available at the time, to