8 TOPOGRAPHY AND GEOLOGY. 



have pointed out that the Old Red Sandstone, where now exposed, once 

 bore upon its back the thick mass of Carboniferous Limestone, and this in 

 turn was covered by the Coal Measures. The loss of the latter is surely 

 atoned for by the magnificent mountain-scenery to which the Old Red 



Sandstone has given rise. The Reeks of Kerry, the 

 __. , . „^ brown and purple masses of Killarney, the bare and 



Mountains ot Kerry. ^^^^^ rock-walls that look down on so many romantic 



valleys of the west, result from the exposure of the 

 lake deposits of Devonian times. The terraced structure of the original 

 stratification, bed upon bed, is characteristic of these mountain-sides, and is 

 nowhere more clearly seen than in the neighbourhood of Derrynane and 

 Waterville. On the east, the anticlinal ridges are more rounded and broad- 

 backed ; but fine craggy combes occur in the Galtees and in the Comeraghs, 

 and the Old Red Sandstone country is still given over to moor and heather. 

 (Fig. 5)- 



The contrast between the scenery of the Old Red Sandstone and that 



of the easily denuded Carboniferous strata is finely 



^.., revealed around Killarney. The Upper Lake lies 



1 any. among the mountains ; the Lower Lake, with its flat 



northern shores and its low islets, lies on Carboni- 

 ferous Limestone, and reminds one of the features of the central plain. 



In the Dingle Promontory, a great unconformity separates two divisions 

 of the Old Red Sandstone. The earth-movements disturbed the lower 

 beds during the course of the Devonian period, and the later strata were 

 laid down across their upturned edges. Were these movements belated 

 relics of the Caledonian folding, or precursors of the Hercynian ? At 

 various points we meet with evidence of this kind, showing that the crust is 

 never really at rest, although we mark out certain epochs of calm, and others 

 marked by strenuous folding. 



The Coal Measures still remain spread across the country from Killarney 

 to Galway Bay, but are unproductive from a mining point of view. They 

 have been swept off eastern Limerick and from most of Tipperary ; in the 

 mountains round Lough Derg and in the Galtees, even the Old Red Sand- 

 stone has been cut through, and the Gotlandian and Ordovician rocks have 

 come to light. But a broad synclinal lies between the joint Slieve Bloom 

 and Devil's-Bit Range and the Leinster Chain • and 

 The Kilkenny in the centre of this the high Kilkenny Coal-field 

 Coal-field. stands. The Barrow on the east, and the Nore on the 



west, have cut out valleys which limit the intervening 

 ■mass of Coal Measures ; from either stream, the ground rises to the 

 plateau of Castlecomer, in a series of scarps which remind one of those of 

 "Yorkshire, or of the edges of the similar synclinal coal-field of the Forest 

 •of Dean. The coal is anthracite, but has long been mined for local purposes. 

 On the west of the Coal Measures of this area, where the head-waters of 

 the Suir and the Nore have exposed the Carboniferous Limestone, the 

 country is a fairly level and plain-like region, in which the rivers wander. 

 When, indeed, we round the coal-field at Stradbally, we look out over the 

 true plain of Kildare, where brown bogs gather in the hollows, the haunt of 

 plovers and nestUng gulls, and where green demesnes and broad meadows 

 speak of the fertility of the soil. Here there is no rapid repetition of sand- 

 stone ridges and softer pastoral synclinals ; on tlie other hand, one vast 

 and shallow synclinal stretches from the Slieve Bloom Range to the Ox 



