ON THE GEOLOGY OF THR LAKE DISTRICT OF KILLARNEY. 97 
The Society met on the 9th of January, 1856, on which occasion 
the following Paper w r as read. 
ON THE GEOLOGY OF THE LAKE DISTRICT OF KILLARNEY. 
BY MR. GEO. Y. DU NOYER. 
The district to be described comprises in superficial extent an area 
of about 100 square miles, inclusive of the Lakes; and is marked on 
the Ordnance Survey Index of the county of Kerry as sheets 65; 
southern half, 66, 73, 74; and the northern halves of 83, 84. It will 
be seen, therefore, that Carrantwohill Mount, Macgillicuddy’s Reeks, 
and the Black Valley, the Range of Knocknabreda, with Croma- 
gloun and Tore Mountains, the rocky ridge terminating in the Eagle’s 
Nest, Cliff, Mangerton, and the Devil’s Punch-bowl, are included 
in this area. 
As he proposed noticing the rocks in descending order, he had 
first to speak of 
THE COAL-MEASURES. 
These occupy but a small portion of the district, and constitute 
its northern boundary, forming the low ridge of ground on which the 
old church of Aghadoe stands. They consist of thick beds of dark 
gray, splintery shale, often almost black, and sometimes presenting 
a concretionary structure. Through these shales are thick and 
thin bands, and often sets of beds of hard gray and olive gray grits, 
in the thinner layers of which, impressions of coal plants are not 
uncommon. The only point of present geological interest connected 
with these coal-measures is the fact, that wherever they can be well 
observed along their southern boundary, they invariably dip to the 
south from 30° to 65°,—thus appearing to underlie the Carboniferous 
Limestones. As this discrepancy in the dip is persistent for many 
miles from the west of Killarney to Mallow, a distance of fully 50 
miles, it can only be accounted for by supposing either a fault, or 
an inversion of the beds by contortion. 
CARBONIFEROUS LIMESTONES. 
In Muckross Demesne occurs the most perfect development of 
the Carboniferous Limestones of the Killarney district. The upper¬ 
most beds there, or those which occur in the eastern portion of the 
Demesne, are all of a light gray colour, close-grained and finely la¬ 
minated,—a structure apparently in many instances due to cleavage; 
