F. R. Cowper Reed — Carries of Comeragh Mountains. 155 



a total thickness of 3,200 feet, and consists of a locally developed basal 

 breccia followed by about 1,000 feet of brownish-red conglomerate 

 of various degrees of coarseness ; and this is succeeded by reddish- 

 brown shales, sandstones, grits, and strong conglomerates, with 

 many white quartz pebbles, reaching a thickness of about 2,200 feet. 



The jointing of the Old Red Sandstone rocks, both conglomerates 

 and sandstones, is strikingly complete and well developed ' ; and the 

 presence of these divisional planes and lines of weakness has an 

 intimate connection with the production and preservation of the 

 precipitous walls of the corries. The alternation of hard and soft 

 beds of rock is clearly brought out by weathering in the cliff-faces 

 of some of the latter, such as Coumshingaun, and results in the 

 formation of successive small vertical cliffs or scars alternating with 

 benches and talus slopes, expressing the vertical heterogeneity in the 

 profile. 



Orography of the District. 



The Comeragh Mountains form a mass of high ground at the 

 western end of co. Waterford, their main axis running nearly north 

 and south ; they rise to a maximum height of 2,597 feet above sea- 

 level, and break off suddenly towards the east in a more or less 

 regular escarpment, the summit of which is in most places over 

 2,000 feet high, but it sinks down gradually and loses its character 

 to the north and south. The northern part of the range is sometimes 

 known as the Reeks of Glenpatrick, and joins on to the line of lower 

 rounded hills bordering the south side of the River Suir. The 

 platform of older rocks which stretches away to the east with 

 a gently undulating surface from the foot of the mountains is known 

 as the plateau of Rathgormuck, and has an altitude of only 300-500 

 feet above the sea. On the west side the whole mass of the Comeragh 

 Mountains is separated from the Knockmealdown Mountains by the 

 long pass or valley of Ballynamult, which runs southward from the 

 valley of the Suir. Behind the escarpment the Comeragh Mountains 

 are deeply trenched by the valley of the Nier, which runs in 

 a westerly direction so as almost to bisect them. This river, which 

 ultimately joins the Suir just east of Newcastle, drains the greater 

 portion of the western slopes and receives several tributary streams, 

 some of which flow down from the cirque-headed valleys on its 

 south side. The northern flanks of the mountains shed a few short 

 unimportant streams direct into the Suir ; and the south-west slopes 

 are drained by the Colligan, which flows south into the sea at 

 Dungarvan. The eastern escarpment, traced from its northern end, 

 runs at first south-east at the foot of the Reeks, but at a point just 

 south of Knockanaffrin Mountain it turns to the east, and continues 

 in this direction for over one mile, forming a large embayment, 

 at the bend of which is the important gap and pass into the head of 

 the Nier Valley. This pass makes a conspicuous dip in the fairly 

 uniform summit-line of the mountains, being only 1,500 feet above 



1 Haughton, "On the Physical Structure of the O.E.S. of Co. 'Waterford": 

 Trans. B,oy. Soc. Dublin, 1858, pp. 333-348. 



