GEOLOGICAL SOCIETY OF DUBLIN. 23 



Some good sections of the lower beds of the limestone, and the rocks 

 immediately beneath, are seen here and there along both the northern and 

 southern boundaries, but particularly the latter. I shall notice two or 

 three of these sections proceeding from the town of Kenmare eastward 

 to Kilgarvan. At Eoughty Bridge, about two miles from Kenmare in 

 this direction, we have a section which, in descending order, consists 

 of the following rocks : — First, blue and gray thick-bedded limestone, 

 with crinoidal fragments ; then abed of pale purple crinoidal limestone, 

 which rests upon blue and black shales and slates, in the upper part of 

 which are thick calcareous bands abounding with fossils.* These beds 

 rest again upon hard gray and yellowish gray grits, with narrow beds of 

 gray gritty slates, also fossiliferous. The latter beds are particularly 

 well seen under the principal arch of Eoughty Bridge. And, finally, 

 these beds rest upon dull red and purple slates and grits, with occasional 

 green bands, the upper portion of which are often calcareous. The thick- 

 ness of these rocks here, between the limestone and the red slates, is 

 about seventy feet ; at the Bridge they all dip to the north at about 70°, 

 but become nearly flat and are much twisted immediately under the 

 Bridge to the south, both in the river and on the opposite side from this 

 spot. The black shales and slates on which the limestone rests are seen 

 to dip suddenly to the south and north again, thus forming a small basin 

 or trough of the lower beds of the carboniferous limestone at this place, 

 about a quarter of a mile west of Eoughty Bridge, and immediately south 

 of a place called White House on the map. The limestone is seen dip- 

 ping north at 80°, and a little north of this again, in an old quarry on 

 the edge of the Kenmare road, opposite Killowen House, the limestone 

 is seen to dip south at 70°. The dip here is well marked by a bed of soft 

 black shale, which divides the thick beds of gray crystalline limestone. 



The next place where the dip is well seen in the limestone is in 

 crossing the valley to the north, in the Cleady river, close to Kilpatrick 

 grave-yard, where there is a well-marked dip of 55° to 70° to the south; 

 and further along the northern boundary of the limestone, at Ardtully 

 copper mine, where the limestone is well exposed and fossiliferous, the 

 dip is observed to be north at 80°. Thus it will be seen that the lime- 

 stone forming the valley of Kenmare does not dip uniformly to the north 

 from the southern boundary, or south from the northern boundary — 

 thus forming one simple synclinal trough of great thickness — but is 



* Mr. Salter has been kind enough to give me the following list of fossils got near 

 Eoughty Bridge : — 



Fossils of Carboniferous Slate overlying the thin beds of Argillaceous Sandstone. 



Spirifer disjunctus. — Sow. 

 Strophomena crenistria. — Phill. 

 Orthis filiaria.— Phill. 

 Stems of Actinocrinus. 



„ Poteriocrinus. 



„ Rhodocrinus. 

 Fenestella, rare. 



