255 
Geological Relations of the East of Ireland \ 
somewhat different ; the limestone there constituting basins, with 
strata rising and cropping out around them, and including within 
distinct coal districts, each supported by its base of limestone, two 
of which are especially deserving of notice ; but beyond the bor- 
ders of these basins, the dip of the limestone appears to depend, as 
already observed, upon the position of the surface of the older 
rocks, with which it comes in contact. Again, in the south- 
western quarter of the field, the prevailing dip in the interior is 
toward the west or south ; but the same rule still holds with respect 
to the portions contiguous to older rocks. 
Such is the predominating arrangement throughout the limestone 
tract ; but local variations are to be found in different parts, de- 
pending, however, partly on mere inflection. Thus, in a line 
drawn from the grey wacke country east of Athy past Maryborough 
to the west, we perceive the general arrangement to approach to 
the horizontal, with a slight dip of 8° or 10° toward the south ; 
but in the rock of Dunamase, one of that small range of limestone 
hills, which stretch across the northern front of the Castlecomer 
coal district, (see Plate A. No. 2.) we may observe some remarkable 
inflections. The rock, on which the castle stands, presents a mural 
precipice to the north, the strata generally inclining about 12° to- 
ward the south, yet undulating both in the line of direction and 
of dip. And in the inclosure on the summit, some of the strata 
ascend from the south under an angle of 50°, and suddenly become 
inclined toward the north under an angle of 40°, the inflection thus 
amounting to 90°. The strata which dip 40° toward the north 
are surmounted by others which dip only 20°. Again, the vene- 
rable remains of the ancient cathedral of Cashel are supported by 
a broken arch of concentric strata of limestone. They constitute 
the celebrated rock of Cashel, the subjacent arches of which are 
