340 PEOCEEDINGS OP THE GEOLOGICAL SOCIETY. [Mar. 7, 



At the extreme southern point of the head they consist of hard 

 greenish-grey grits, which we at first took for the upper part of the 

 Old E,ed Sandstone, but which are the same as those afterwards 

 called the Coomhola grits. 



These undulate in very regular troughs and saddles, dipping north 

 and south respectively at angles of 40° or 50°. Over them comes a 

 great series of grey slates and grey and greenish grits, the dip being 

 steady to the north at 60°, for a distance of a mile and a half. The 

 beds then become more purely argillaceous, black shining slates, with 

 occasional bands of nodules, and grey slate weathering to a light- 

 green tint with a soapy feel. The cleavage is often vertical, but in 

 Holeopen Bay was noted by Mr. Du Noyer as dipping to south-south- 

 east at 60°, and again in another place to north-north-west, at 80°. To 

 the northward of Ringalusky point and Black Head, undulations occur 

 again in beds of grey slate, but still with a general dip to the north, 

 until we reach Ballymackean on the east coast, and Lispatrick Lower 

 on the west, where the promontory unites with the main outline of the 

 coast. The slates here are black, and carbonaceous, and on the 

 Lispatrick side there occur numerous specimens of Posidonomya 

 Becheri, Goniatites, and small Orthoceratites, making it probable that 

 we here again have some of the basal shales of the Coal-measures 

 brought in on the top of the Carboniferous Slate. Immediately to 

 the north of this the beds rise again to the north for a long way, as 

 may be seen by following the cliffs, eastwards towards Kinsale Har- 

 bour, or westwards along the shores of Courtmacsherry Bay. 



Mr. Du IToyer, after making all allowance for the undulations of 

 the beds, calculated that the thickness exposed in the cliffs of the 

 Old Head promontory cannot be less than 6500 feet (see Explanation 

 of sheet 194, &c. p. 23). 



9. Cape Clear and Mizen Head Antidinals. — Between Ballinhassig 

 and the Old Head of Kinsale, a distance of 15 miles from north to 

 south, no Old Eed Sandstone reaches the surface from underneath the 

 Carboniferous slate, notwithstanding the numerous anticlinal and 

 synclinal curves which run through the country. Proceeding towards 

 the west, however, two main anticlinal ridges of Old Eed rise 

 gradually from underneath the Carboniferous slate, increasing in 

 width and importance as we proceed further west, and terminating, 

 the southern one in Cape Clear Island, and the other in the Mizen 

 Head. Minor undulations also bring up the Bed Bocks on both 

 sides of Clonakilty Bay, forming the headlands called the Seven 

 Heads and Galley Head, and also in Bearing Water Bay, continually 

 sub -dividing and narrowing the area of Carboniferous Slate. 



The Old Bed of the Mizen Head anticlinal makes its first appear- 

 ance in the hill of Knockawadra, 5 miles south of Dunmanway *, 

 stretching thence to the Mizen Head. It was on the south side of 



* In our published maps, this anticlinal is marked as showing Old Red Sand- 

 stone several miles farther to the eastward ; but I now believe that the strong 

 green grits and slates which were at jSrst supposed to indicate the top of the Old 

 Eed Sandstone, belong in reality k) the Coomhola grits in the Carboniferous 

 Slate. 



