239 
Geological Relations of the East of Ireland. 
5 137. This red sandstone conglomerate re-appears in the 
range of hills near the town of Kildare; (see Plate 6 . No. 1 .) 
Red hill, Dunmurry hill, and the western foot of Grange hill, con- 
sist of alternating beds of fine grained greywacke, gfeywacke slate, 
and clay slate, ranging 10 ° north of east and south of west, and 
dipping 60° toward the south-east, but in many places being nearly 
vertical. At the northern foot of Red hill, is a small patch of red 
sandstone conglomerate, which was quarried for millstone about a 
century since. At present little of the firm rock is exposed to 
view, but enough is visible, at the well, to show that the strata 
range east and west and dip 17° north. 
The Chair of Kildare consists of floetz limestone, extending 
southward to the northern foot of Dunmurry hill, and apparently 
covering in this quarter the greywacke and slaty rocks. To the 
north it rests on the trap of Grange hill, which also appears to 
cover greywacke and slaty rocks. The hill of Allen is separated 
from Grange hill by an intervening vale, their summits being about 
two miles apart. The former is wholly composed of trap ; but 
whether a distinct mass, or connected with that of Grange hill, is 
not easily ascertained from the depth of alluvial soil. At the 
northern extremity of the hill of Allen, about one quarter of a mile 
distant, is a slight eminence, called the Leap of Allen, composed of 
red sandstone conglomerate, arranged in beds which vary from nine 
to eighteen inches, and even to two feet six inches thick, and are 
separated by thin layers of reddish sandy slate clay. This contains 
the same components as the conglomerate already noticed, with the 
addition of fragments of greywacke slate, which are however com- 
paratively rare. It is quarried for mill stones, the best of which sell 
on the spot for seven guineas and a half the pair. The beds range 
north-north east and south-south west, dipping south-south east, at 
an angle of 15° to 20°; and hence they probably underlie and 
