DU NOYEE — ON THE SOUTH OF IRELAND. 
245 
boulders poised oue over the other, and these could only have been 
placed in their present position by having been slowly dropped from 
an iceberg as it melted from the heat of summer. Had such a piling 
of angular blocks occui'red under water and within reach of any float- 
ing mass of ice, it would have been thrown down by the first con- 
cussion. 
As the land still slowly emerged from the sea, the disintegrated 
materials from its shores became more or less sorted by the action 
of the tides and currents, and arranged in certain localities most fa- 
vourable for their reception. Thus, the low^ ground which extends 
from Killarney to Millstreet, lying at the northern base of the 
mountains commencing at Carrantuohill and Skreaghmore on the 
west, and including the Eeeks, Maugerton, Stoorapa, Crohane, the 
Paps, and ending in the range of the Caherbarnagh mountains on 
the east, is covered by a thick accumulation of well-rounded, coarse 
Boulder-Drift, all derived from the rocks of the neighbouring moun- 
tain chains ; being, in fact, the sweepings of the sea from out their 
various valleys and gorges. Although this Drift is spread out on 
the Carboniferous limestone which extends along the flanks of the 
mountains, it is quite free from any fragments of that rock — a fact 
which aids in determining the origin of the deposit. The highest 
elevation to which this Drift reaches up the flanks of the mountains 
at Mangerton is about 600 feet ; and in the neighbourhood of Kil- 
larney, along the road to Muckross, this deposit is escarped to the 
depth of 300 feet. 
One of the most clear and unmistakable examples of an erratic 
ice-borne block, or perched boulder, is to be seen near Kenmare, in the 
county of Kerry, on the hillside about half a mile to the south of 
lloughty Bridge (Fig. 1, p. 241). It consists of a large and nearly 
rectangular block of grey, thin-bedded, cherty limestone, formed of 
a series of beds which have come away from the main mass along 
two sets of joint planes, which cut each other nearly at right angles. 
This boulder is known by the name " Cloughvorra ;" it measures 
2G feet from north to south, 16 feet from east to west, and is now 
about 15 feet to its highest point above the ground. This remark- 
able block rests directly on purple grits and slates of the Old Eed 
Sandstone, the beds of which dip to the N.N.W. at 60°. The ele- 
vation of "Cloughvorra" above the sea is 260 feet, while no lime- 
stone in the valley of the Eoughty river reaches a greater elevation 
than 200 feet, and the average height of the limestone in the valley 
