338 Kinahan — Ancient Sea Margins. 



taking place ; but in some parts where master-joiats occur, two 

 or more of the above-mentioned terraces are merged into one, 

 and when the master-joints are perpendicular or oblique to the 



Block Beacli. 



y^f'' //'' " '^~^' \ High Spring Tides. 

 ^^^; ^ ^ ~ '^ High Neap Tides. 



"^ "" "" //7r\ . Intermediate Terraces. 



I o-n* Neap Tides. 



~Mfi Low Spring Tides. 



Fig. 1. — Diagrammatical Section of Cliffs on the West Coast of Inishmoee. 



direction of the force of the waves, the destruction is much more 

 rapid, giving rise to high, imbroken, precipitous cliffs. 



The Burren Mountains display very similar results. In numerous 

 places there are escarpments formed of from four to seven terraces 

 cut out of the nearly horizontal beds of the Carboniferous Lime- 

 stone. These continue for miles, but in places they apjpear to have 

 been affected by the varying conditions found on the west coast 

 of Inishmore. This is exhibited in the accompanying sketch of the 



Fig. 2. — Hills East of Glencolumbekille, looking ISTorth-east. 



hills on the east margin of Glencolumbekille, taken by my old friend 

 and colleague, A. B. Wynne, P.G.S., now of the Geological Survey 

 of India (see Fig. 2). 



In the neighbourhood of Black Head, the north-west point of the 

 Burren, the ancient sea-margins are very apparent when viewed 

 from Tar-connaught, which lies immediately north of Galway Bay. 

 Here an observer will remark three sets of terraces forming con- 

 spicuous escarpments as shown in Fig. 3.^ 



1 The wood-engraver has not succeeded in this sketch ; he has given the idea of 

 three hills, instead of a mountain with three peaks, and has not continued the 

 terrace to Cappanawalla. 



