163 
Stratified Rocks near Killarney a7id Dublin, 
Currawiitoohill mountain*, from whence clipping to the south- 
ward it is covered by siliceous sandstones of a greenish or 
brownish colour;” and this view is illustrated by a section 
given in Plate I. fig. 3, which, together with those contained 
in your Magazine, exhibit the whole of his views on the sub- 
ject. 
For the sake of clearness, I have also prepared two sec- 
tions passing nearly through the same line of country as those 
given by Mr. Hamilton, from which it appears that the old 
red sandstone on the summit of MacGillacuddy’s Reeks, rests 
conformably on the schistose rocks of the gap of Dunloe, 
which Mr. Hamilton terms Cambrian ; and that the apparent 
unconformability which is visible nearly in the centre of the 
gap between the chloritic quartz rock and the old red sand- 
stone, has been occasioned by a great north-west and south- 
east fault, which crosses the gap of Dunloe nearly at right 
angles, and extends from thence in a south-eastern direction 
along the northern declivities of the Purple, Toomies, and 
Glena Mountains, from whence in continuation it reaches the 
lower Lake of Killarney, near the Glena Cottage Banqueting 
House, thence it crosses Brickeen Island, and passing through 
Turk Lake reaches the north base of Turk mountain. 
This fault may be said to form the key to the geology of 
the Killarney district, as it explains the apparent anomaly 
deducible from the persistent dip to the south of the strata 
on both sides of Glena Cottage and Brickeen Island, which 
might lead, and has led incautious observers to infer that 
the strata belonging to the transition slate series which occur 
to the south of the fault rest conformably on the top of the 
old red sandstone of Brickeen Bridge, of the northern part of 
Brickeen Island, and likewise on the carboniferous limestone 
east of Turk Cottage. 
In expressing my view of the geology of the district, I shall 
commence with the west side of the Gap of Dunloe; but here 
my section, Plate II. fig. 1, is so difierent from Mr. Ha- 
milton’s, that it is with difficulty we can recognise them 
as being intended to represent the same locality ; yet such is 
the case. Of the accuracy of my own section I entertain no 
doubt, having made it with great care. 
In taking a sectional view of the strata as exhibited on the 
west side of the Gap ofDunloejthe first beds visible at the sur- 
face consist of a reddish gray quartzose rock belonging to the 
old red sandstone formation. These are succeeded by a 
series of thick beds, of coarse-grained conglomerate com- 
posed of rounded pebbles of white quartz, varying in size 
* The highest of the Reeks. 
M2 
