GEOLOGICAL SOCIETY OF DUBLIN. 25 



lower beds of the limestone, and the beds immediately beneath it, which 

 we have traced from Roughty Bridge to Kilgortaree House, a mile dis- 

 tant from this point. "We see no trace of these beds along here between 

 these points. The fact of a fault existing here along the southern 

 boundary of the limestone would account, in some measure, for the sudden 

 narrowing and apparent thinning of the limestone, as well as the absence 

 of the beds beneath it at this point. I shall now trace the limestone 

 eastwards to Kilgarvan village, where I think there is further evidence 

 of the existence of an east and west fault, which commences a little 

 south-east of the village, and follows nearly the course of the river 

 Roughty westwards, terminating nearly opposite Clantoo, where the 

 limestone suddenly becomes so narrow. Prom the river Roughty, south 

 of Kilgarvan, up to that village, we see a good section of the rocks. 

 In the river we have dull red and purple slates, parts of which are calca- 

 reous; these beds strike nearly east and west, and dip north at 85°; about 

 200 feet north of the spot, we find strong beds of limestone and black 

 shales striking south-east, and dipping south-west at 45°. Thus, these 

 beds, if prolonged in this strike, would abut against the red slates, which 

 are seen in the river to strike east and west, and dip north at 85°. There- 

 fore, there must be a fault here running nearly east and west down the 

 river Roughty, which cuts off the lowest beds of the limestone, as well 

 as the band of black and blue shales and grits, and the band represented 

 by No. 2 in the accompanying section, which is the upper part of the 

 Old Red Sandstone containing the yellow beds : — 



Section across Kenmare Valley, half a mile west of Kilgarvan, on the scale, both vertical 

 and horizontal, of two inches to one mile. 

 a. Road. 4. Lower Limestone. 



6. Road. 3. Carboniferous Slate. 



c. Roughty river. 2. Yellow Sandstone. 



d. Glebe-house. 1. Old Red Sandstone. 



e. Kenmare road. 

 /. Stream. 



g. Owbeg river. 

 h. New road. 



I shall now draw your attention to the ground north and north-west 

 of Kilgarvan, through which this section is drawn. It is drawn from 

 Carrigagreenane Hill, about two miles and a half north-west of Kilgar- 

 van, to a stream south of Carrignagown Hill, about two miles south- 

 west of Kilgarvan. I shall commence at the river Roughty, and notice 

 the rocks seen in the section to the northern end. We see, first, this 

 band of limestone forming a band along the northern side of the river 

 Roughty ; the dip of the beds seem to be south from the road to Ken- 



VOL. VT. v. 



