141 
i . , 
Geological Relations of the East of Ireland \ 
On the eastern brow of Rochetown-hill, above the road, is a 
natural hollow in the granite, into which mica slate runs to a point 
toward the north, ranging north-east and south-west, and dipping 
75° south-east, while to the south and south-east it expands over a 
part of the eastern face of the hill. The western side is formed by 
the granite crest of the hill above, against which the mica slate leans, 
while the eastern side of the hollow consists of a ledge of projecting 
granite rocks. The western demarcation is remarkably distinct, 
forming a direct line of nearly one quarter of a mile in length, the 
granite rising as a wall four to six feet above the mica slate in the 
northern part, but increasing in the southern to ten, and even fifteen 
feet in height. The northern, western, and southern sides of Roche- 
town-hill are wholly composed of granite, which protrudes in many 
places. 
§ 22. The cultivated soil now prevents farther observation, until 
we ascend the hills more south, where mica slate re-appears between 
Shank-hill on the east, and Ballycorus and the Scalp on the west* 
occupying about three- fourths of the range of the hill to the north, 
where the fundamental granite again protrudes in that direction. On 
the southern side of the Scalp, the former rock is seen resting upon 
the latter, inclined at an angle of 35° toward the south-east, and 
ranging 35° north of east and south of west across the Scalp ; but 
the general mass ranges through the hill in the direction of 20° 
north of east, and its dip is 40% as shown in a pit sunk in the mica 
slate to the east of Ballycorus. To the south of this shaft, a 
boundary fence extends over the hill in that direction, in the whole 
line of which the mica slate is exposed, ranging as already stated. 
In the southern quarter, this rock is interstratified with several 
thin beds of fine grained granite, varying in thickness from two 
to six inches and more, sometimes containing minute crystals of 
