170 
JOURNAL OF THE GEOLOGICAL SOCIETY OF DUBLIN. 
south of Lough Nabroda than on the west, which is caused by the 
before-mentioned fault. Where it ends, the grit and slate rocks ap¬ 
parently rest conformably upon it, the dip being S. E. at 50°. East¬ 
ward from this, the line of junction is not plainly seen; but it evi¬ 
dently coincides with the strike of the grits, which is W. 30° S., and 
E. 30° N. A bed of light-green ash lies between the trap and grits; 
the trap ends abruptly a little N.W. of a small mountain lake called 
FoiladuaneLake; but the ash bed is traceable further, till apparently 
cut off by another large fault bearing nearly N. and S., and passing 
just W. of Foiladuane Lake. Just N.W. of Foiladuane Lake are two 
singular square-shaped masses, composed either of ash or of soft 
cleaved trap, with a band of slate and grit between them, dipping at 
50°, and cut off on each side by faults, no trap of any kind appear¬ 
ing beyond them. 
“ Between the range of trap just described, and the summit of 
Crohane Mountain, the rocks are thrown into a bold synclinal curve, 
which brings in the trap, again dipping north, and forming all the 
upper part of Crohane. This trap of Crohane is apparently an iso¬ 
lated basin of trap, with a mass of slate and grit resting in the hol¬ 
low of it, on the northern slope of the mountain, running through 
Lough Athovynastooka; both sides of the basin ending abruptly a 
little east of that lake, probably cut off by a great N. W. and S. E- 
fault. A very well-marked fault, a continuation of that from Foila¬ 
duane Lake, cuts through the middle of this trap, where the little 
mountain track runs up the north slope of Crohane, from the Glen- 
flesk Valley. A bed of green, flaky ash rests upon all the trap of 
Crohane, with red and green grit reposing on it, and sometimes alter¬ 
nating with it, the two rocks occasionally forming a breccia .”—From 
Mr. Juices' Notes. 
On the south side of Crohane the trap is generally a greenish, 
porphyritic felstone, having in places white concretionary nodules, 
varying in size from a nut to a turkey-egg; these nodules being 
very numerous near the summit. 
In some places it is a hard, compact, brownish felstone, with 
crystals of felspar; and there are several beds of dark-green ash. 
There are a few instances of the columnar structure here also. A 
dyke of pinkish felstone cuts N. W. and S. E. through part of the 
anticlinal, on the S. E. slope of Crohane. 
Another large trappean mass occurs at Glenflesk, at a distance 
