Silurian Rocks of the South of Ireland to those of North Devon. 137 
of disturbed, metamorphosed, and denuded Lower Silurian rocks), strata of different 
horizons, belonging to the Upper Silurian series, come in contact with the former, 
according to locality. On a general review of the case, however, we may safely 
assert that the uppermost beds on the banks of the Killaries represent a portion 
of the Dingle and Glengariff beds. There are other resemblances, such as the 
occurrence in both districts (those of Dingle and the Killaries), of contemporaneous 
voleanic products, all tending to confirm the view of the identity in age of these 
formations. The corresponding series in the two districts may thus be repre- 
sented :— 
Representative beds of the Upper Silurian Series in Kerry, West Mayo, and Galway 
(Descending Order). 
Kerry (including Dingle). 
3. Upper Slate Series.—Red and purple slates 
of Dingle Harbour, Kenmare, Sneem, &e. ; 3,000 
feet. 
2. Glengarif Grits —Massive green and purple 
grits, sometimes pebbly, forming the mountains of 
Brandon, the Reeks, and of Killarney, Glengariff, 
&c. ; about 8,000 to 10,000 feet. 
1. Smerwick and Sybil-Head beds.—Lying at the 
base of the Dingle section. Purple, brown, and 
green sandstones, flagstones and shales. 
I].—Relations of the Gilengariff 
West Mayo and Galway.* 
3. Salrock Slate Series.—Bright red slates, with 
grits, and a band of limestone, with fossils. Lin- 
gula, Pterinza, Trochus, &. ; 3,000 feet. 
2. Mweelrea Beds —Green and purple grits and 
conglomerates, with beds of slate and shale and 
contemporaneous trap rocks ; 8,000 feet. 
1. Owenduff Series (Upper Llandovery).—Green 
and grey grits, sandstones, shales, &c., with fossils. 
Favosites, Orthis, Atrypa, Trochus ; 2,000 feet. 
Beds to the Old Red Sandstone 
and Carboniferous Beds. 
The highly discordant position of the Glengariff beds to the Old Red Sandstone 
and Conglomerate in the Dingle promontory is recognised by all observers, and is 
of a very striking and trenchant description.t But it has been denied, or else not 
generally recognised, that any such discordancy exists in the mountainous region 
lying along both shores of Kenmare and Bantry Bays. For myself, I had enter- 
tained for a considerable period a doubt as to the supposed conformity of the Glen- 
gariff beds to the south of Dingle Bay ; but it was not till the year 1877 that I had 
a favourable opportunity for making a personal examination of this district. 
Having, in the summer of that year, made arrangements (with the concurrence of 
the Director-General) for a tour of investigation, I examined various sections 
throughout the promontory of Dingle, the districts of Killarney, Kenmare, Sneem, 
and Glengariff. In this tour I was accompanied by Mr. J. O'Kelly, m.n.t.a., and 
Mr. Alexander M‘Henry, officers of the Geological Survey. The general result 
was that, both along the shores of Kenmare and Glengariff Bays, we found the 
clearest evidences of a great Mvatus between the Glengariff beds and those which 
* Expl. Mem. Geol. Survey, sheets 93, 94, &e., p. 15. 
+ Hor. Section of the Geol. Survey, sheet 15. “‘ Explanation,” sheets 160, 161, and 171. 
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