Coffey and Prakger — The Antrim Baised Beach. 147 



Another well-marked erosion feature, proving emergence of the 

 land, is the occurrence of sea-caves at a level higher than that at 

 vrhich their formation hy vrave-action would he possible. Such caves 

 may he studied with advantage at the basaltic cliffs of the Gobbins, in 

 ■County Antrim, where the tide now enters them only at or near high 

 water. Again, west of Ballintoy harbour, some of the caves cut in 

 the chalk have been sufficiently elevated to be used as boat-houses and 

 stores. At Ked Bay, in the same county, a row of caves may be seen 

 on the inner side of the Antrim Coast road, cut in the IS'ew Red Sand- 

 stone, some of which were till recently used as dwellings. 



Deposition Phenomena. 



The phenomena of deposition are more extensive and varied, and 

 lend themselves more readily to detailed study. As the land sank, 

 allowing the sea to make inroads into the drift and other soft deposits 

 of the land margin, the eroded material, and that brought down by 

 streams, was deposited along the coast. On the more open shores, or 

 where currents prevailed, these beds consisted mainly of gravel and 

 sand; in the deeper or quieter waters, mud was laid down. On 

 and in these deposits, in many places, a varied fauna flourished, the 

 nature of which, as gleaned from the shells and other harder parts of 

 the animals which still remain, often furnishes valuable evidence as 

 to depth of water and other conditions under which this fauna lived. 

 These old sea-beds, shoals, and beaches, by subsequent elevation, have 

 been raised above high-water mark, or, though still submerged, are now 

 Seen at levels higher than those at which they were deposited. 



The Raised Beach Deposits. 



These raised beaches and sea-beds are finely developed in the 

 north-east of Ireland, the latter even better than the former. The 

 famous raised beach of Larne is a gravel-bank, a long tapering ridge, 

 heaped up by tides, extending from the narrow entrance of Larne 

 Lough for some three-quarters of a mile into the waters of the bay 

 (Plate IV.). The material of which it is composed is stratified gravel, 

 with sandy beds (Plates YI., VIL) ; the latter often exhibit colonies 

 of burrowing bivalve shells, still in the position in which they lived. 

 All the layers yield abundant specimens of the commoner univalve 

 shells which crawl about between tides or in shallow water. With 

 these shells, as will be referred to later, flints worked by man are found. 



