Geological Relations of the East of Ireland, 187 
scarcely ever free from them, and they are sometimes almost innu- 
merable. 
Quartz rock, when in mass, is unstratified, but it frequently 
presents in this respect a deceptive appearance at the surface; 
being traversed by nearly parallel fissures, intersecting each other 
obliquely, which thus tend to divide the rock into rude rhomboidal 
portions. Examples of this kind may be seen in the two Sugar 
Loaves, and Bray Head ; and in this respect we perceive some 
analogy to granite. It is only when interstratified with the other 
rocks that quartz rock appears in distinct beds ; as, for instance, in 
the southern part of the rocky coast called the Greystones, situated 
about a mile and a half to the south of Bray Head* 
The stratified beds in association with quartz rock exhibit, in 
some parts of their course, considerable inflections, both on the 
large and the small scale. 1 he former are probably in a great 
measure derived from the shape of the inclosed unstratified mass 
of quartz, along the flanks of which they sweep. Thus, on the 
north bank of the Dargle river, a great unstratified mass occurs, 
flanked on either side by the stratified rocks ; those on the western 
side ranging 15° south of east and north of west, and dipping 50° 
to 60° toward the north-east, and those on the eastern side ranging 
SO 0 east of north and west of south, and dipping 75° toward the 
south-east; (§71.) 
§ 80. I have already observed, (§ 22.) that the quartz rock of 
Shank hill, on the north side of the Dargle, (see PL 8. No. 9.) is 
immediately connected with granite, and judging from the structure 
of this granite, it probably passes into it. But on the eastern side 
of Shank hill, the quartz rock appears to be associated with clay 
slate, the shingle of the latter being observable in the fence which 
ascends the hill on that side. On the south of the river, it seems 
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