DU NOTEE — ON THE SOUTH OF IRELAND. 
251 
sloping to the northwards, having the southern face of the boss preci- 
pitous. The current sent the iceberg up the inclined plane facing to 
the northwards, till the shoaling of the water arrested its further 
progress. The sudden concussion thus given to the rock detached 
from off its precipitous brow facing to the southwards large flakes 
of rock, and threw them one on top of the other down the inclined talus 
at the base, just as a lot of books would lie if suddenly thrown down 
on their sides from a previously close and vertical position. It is 
highly probable that the iceberg here permanently grounded and 
melted away, leaving the perched boulder which we now see on the 
summit of the rock as the most palpable evidence of its short-lived 
existence.* 
Erratic boulders of a syenitic granite, a rock peculiar to the county 
Galway, lie scattered over the country to the S. and S.E. of it, com- 
prised in the counties of Clare, Limerick, and Tipperary, and some 
of them are to be seen, as far south as the deer-park of Mallow 
Castle, county Cork. Hence we have a clue to the direction of at 
least the last iceberg current. 
Many Drift boulders may be considered as local, and are due to 
the action of shore ice, which dropped them before they had been 
transported far from their parent site. Of this fact we have an ex- 
ample in a large block of a very peculiar kind of light grey clierty 
limestone, with thin earthy shale layers through it, which rests in a 
field close to the Workhouse of Mallow. It now lies on the coal 
measures to the south of the outcrop of the limestone, and similar 
limestone is observed in sit it is in the. deer-park of Mallow Castle, 
about two miles distant from the boulder, and near the base of the 
Old E-ed Sandstone hills. 
The Musheramore range of mountains, lying between Macroom 
and Millstreet, have Drift gravelly clay resting on their southern sides 
to the height of 2050 feet above the sea, as is apparent on the southern 
slope of Mullaghanish Mountain. The southern slopes of Lacka- 
baun Mountain, up to an elevation of 1500 feet, are dotted over with 
numerous large angular boulders of purple slates and grits. On the 
southern slope of Lackabooma Mountain, at a height of 1270 feet 
above the sea, numerous large angular blocks of hard greenish grit 
are scattered about. And thick accumulations of gravel and boulders 
occur, at elevations of 1000 feet, in the various glens and river valleys 
along the southern slope of the mountains to the N.E. of Macroom. 
* See * Memoirs of the Geological Survey of Ireland,' explanation to sheet 193. 
