154 F. E. Coirper Reed — Carries of Comeragh Mountains. 



II. — Notes on the Corriks of the Comeragh Mountains, 

 Co. Watkrford. 

 By F. R. CowPER Reed, M.A., F.G.S. 

 (PLATE XIII.) 



THE corries and tarns of the Comeragh Mountains have received 

 but scanty attention at the hands of geologists. In the Memoir 

 of the Geological Survey ' dealing with this portion of co. Waterford 

 their position and height are mentioned, and reference is made to 

 some of the glacial phenomena in their immediate neighbourhood, 

 but no connected description of the whole group of corries is given. 

 Kinahan, in his "Geology of Ireland " (1878), pp. 245, 310, refers 

 briefly to them, and inclines to the view that they were cut out 

 by the action of the sea on the flanks of tlie mountains, but that the 

 rock-basins which they frequently contain were excavated by small 

 glaciers. The position of the corries, chiefly on the north and east 

 sides of these mountains, as elsewhere in Ireland, is attributed by 

 him to the preservative action of the ice and snow, which would not 

 melt in them so rapidly (owing to their colder aspect) as on the 

 southern and western slopes, where the corries have been obliterated 

 by denudation effected by ordinary subaerial agents. Carvill Lewis |- 

 refers to the glaciation of the Comeragh Mountains in several places, 

 remarking that they " show signs of glaciation on their north-east 

 side as high as 1,000 feet, up to which height they are rounded off and 

 drift occurs. Above this they are jagged and contain cwms, glacial 

 lakes, and other evidences of small local glaciers." 



The following notes on these interesting corries must be con- 

 sidered to be only of a preliminary nature ; a bathymetrical survey 

 of the lakes themselves is necessary to complete their investigation, 

 but possibly this may not be carried out for years owing to the alisence 

 of boats on their surface or in the neighbourhood and the difficulty 

 and expense in conveying one to them. 



Geological Structure of the District. 



The mountains are entirely composed of Old Eed Sandstone 

 forming a wide flattened arch, or rather dome, of which the beds 

 dip to the north and south respectively into the valleys of the Suir 

 and Dungarvan, while to the west they dip at very low angles so as 

 ultimately to pass under the Carboniferous Limestone in the district 

 of Bally macarbery. But this unilbrmity of structure is modified to 

 some extent by small local folds and disturbances in the beds, the 

 axes of which mostly trend east and west in accordance with the 

 general system of folds affecting the Upper Palaeozoic rocks of this 

 part of Ireland. The eastern portion of the dome has been removed 

 by denudation, exposing at the foot of the escarpment thus formed 

 the much-worn platform of Ordovician rocks, on which the Old Red 

 Sandstone rests with a very strong unconformity. 



The Old Red Sandstone in the Comeraghs is estimated^ to reach 



1 Mem. Geol. Suit. Ireland, Explan. Sheets 167, 168, etc., 186-5, pp. 6, 7, 80. 



2 Ciiivill Lewis: "The Glacial Geolooy of Great Britain and Ireland," 1894, 

 pp. 103, 133, 164. 



5 Mem. Geol. Surv. Ireland, Explan. Sheets 167, 168, etc., p. 14. 



