TRANSACTIONS OF THE SECTIONS. 77 
In the more central parts of Ireland, especially in the Queen’s County, Carlow, 
and Kilkenny, the drift also admits of a tripartite arrangement, and in general 
character closely resembles that of the north; but the whole is often loosely 
described as “limestone gravel”#. In many places the Upper Boulder-clay is 
found reposing on a greatly denuded surface of stratified and sometimes current- 
bedded sand and gravels, or even on the Lower Boulder-clay, as at Coonbeg, 
Queen’s County, south-west of Athy, In the same stream (the river Tagine 
one mile to the west, the whole three members are found superimposed. 
At various places near the town of Carlow, as at the railway bridge and at 
Erindale House, the Upper Boulder-clay is found resting on denuded and current- 
bedded gravels. 
At Archersgrove, near Kilkenny, thick Boulder-clay rests on coarse gravels, 
wae a mile to the south the Upper Boulder-clay lies directly on the limestone 
rock f. 
Besides the places named, a great part of these counties is covered with a very 
peculiar Boulder-clay which is inferred to be the upper, although the base is rarely 
seen. It consists of a confused mass of round water-worn pebbles or paving-stones, 
chiefly limestone, from 30-40 per cent., in some cases being well and deeply 
scratched on the rounded surface. These are huddled together in an wnstratified 
matrix of sandy clay. It cannot be a Lower Boulder-clay, for the pebbles are 
rounded by water action. It could not be relegated to the Middle Sand or Esker 
Series, for the pebbles are well scratched. It can therefore only be Upper Boulder- 
clay. Where Upper Boulder-clay is found resting on the gravels, it contains at the 
base quantities of these rounded and scratched pebbles. 
All these characteristics agree perfectly with its being an Upper Boulder-clay. 
The glaciers which gave rise to the upper clays must have passed in many places 
over the already rounded and stratified gravels with which this part of the country 
was covered, and would of course remove a great. deal of them. This detritus 
becoming mingled together with clay and pieces of unrounded rock from places 
uncovered by drift, would result in a confused mass of pebbles, clay, sand, and 
boulders, and would naturally contain more pebbles than boulders. This is exactly 
the kind of stuff that is visible all around Carlow and Kilkenny. A fine section 1s 
seen in it in the railway-cuttings for more than three miles on each side of the 
latter city f. 
It would be difficult to explain these pebbly Boulder-clays on any. other 
ei than the above, even were they never found lying actually on the 
middle gravels, as they do in some places. 
On the Geological Structure of the Tyrone Coal-fields. By Evwarp T. 
Harvmay, F.0.8., F.R.GS.I., of the Geological Survey of Ireland. 
The Carboniferous rocks of this district appear to resemble somewhat those of the 
northern counties of England. The coal-bearing beds are true Coal-measures, but 
the underlying limestone is split up by numerous sedimentary beds, the calcareous 
members becoming more scarce towards the north, until finally the whole becomes 
similar to the Lower Carboniferous rocks of Scotland, to which horizon Professor 
Hull has referred the Coal-measures of Ballycastle, co. Antrim. They are ees 
covered by newer formations, Permian, Trias, Chalk, &c., to which, as well as the 
existence of some large boundary faults, is due the preservation of the two small 
patches of Coal-measures which form these coal-fields. 
aA succession of rocks in the neighbourhood of Coalisland and Dungannon is 
as follows :— 
* Jukes’s Manual of Geology, edited by Geikie, p. 707 e¢ seg. 
+ Identified as the upper clay by its containing at the base quantities of water-worn 
pebbles, all well scratched. 
t It is noticed in more than one locality in the Queen’s County at a height of 1000 feet 
above the sea on the Coal-measure hills. 
