bed of primitive limestone, before mentioned. It has there a tendency to hornblende rock, while in Bennady-glen it displays a granular texture and a few plates of mica.
2. Greenstone.
I have found greenstone in Ravensdale park, at the foot of the mountain of that name, and on the west side of the Faughel hills. I suspect that in those two instances, the latter particularly, it forms beds in the newest granite.
3. Greenstone slate.
rests against the acclivities of the Mourne mountain, but the strata
never rise very high, seldom exceeding 5 or 600 feet; one instance
only was observed of a hill exclusively formed of this rock, and
that did not attain a greater elevation than about 800 feet.
Attempts have been made to quarry it for roofing slate, and were the works conducted with spirit they might perhaps supply Ireland with as good slate as that now imported from Wales, which appears to belong to the same formation.
The greenstone slate of the Mourne mountains contains apparently no crystallized hornblende in the basis, though it is disseminated through the latter, as is shewn by the manner in which it fuses before the blowpipe. I have remarked in it some crystals
