GLENGARIEFF GRITS AND SLATES. ; Til 
thin-bedded grits of the Carboniferous. All the beds dip towards 
the 8.S.E. at angles varying from 60°-80°. 
6. Not less decisive is the boundary as shown in the fine section 
of the Coomhola river, which flows into the head of Bantry Bay. This 
section is described by Professer Jukes in the memoir above quoted. 
The Coomhola grits, interbedded with grey and black slates with 
Carboniferous fossils, give place, a few yards north of Coomhola 
Bridge, to the massive purple grits and slates of the older formation. 
Supposed conformity of the Glengariff Series and the 
Carboniferous Beds. 
Considering that in the Dingle promontory the Glengariff-erit 
series occupies a position of extreme discordancy to the Old Red 
Sandstone, and therefore to the Carboniferous beds above, there is 
a prima facie reason for supposing that these formations would be 
found in a somewhat similar relationship in the region to the south 
of Dingle Bay. The evidence of this is, however, very small, so 
much so as to give rise to the impression to which I have already 
referred, namely, that, as expressed by Prof. Jukes, “ from the highest 
bed of Carboniferous slate as deep down as observation has allowed us 
to penetrate (into the Glengariff-grit series), is one great and appa- 
rently continuous series of sandstones, or gritstones and clay slates” *. 
It is a common observation how deceptive are such ‘“ apparent” 
conformities, because beds which are widely separated in geological 
time, if they should happen to be similarly placed as regards the 
horizon, may easily be considered continuous. Whether, if the two 
sets of beds forming the Glengariff, Kenmare, and Killarney districts 
were but slightly inclined to the horizon, a clear unconformity would 
be observable, I am unable to say ; it is not improbable. Butif beds © 
which are only slightly uncontormable to each other are both sub- 
jected afterwards to tangential forces, causing them to assume a 
series of sharp flexures, and to rise to the surface at high angles, as 
is actually the case, it is clear that the original unconformity, what- 
ever it may have been, will have been so completely superseded by 
the more recent flexuring that it will be obscured and be incapable of 
observation unless in transverse sections of great depth. It is thus 
I account for the apparent conformity of the Carboniferous and the 
Glengariff grits and slates in the regions now under consideration. 
The tlexuring of the strata along approximately east and west axes 
after the Carboniferous period has been of so intense a nature as to 
completely overmaster whatever discordant inclinations may have 
previously subsisted between the two formations. But whether there 
is a real or only apparent conformity is a question which cannot 
affect the relation of the beds or the determination of their geolo- 
gical position ; certain | am, in any case, there is not a “‘ continuous 
series,” but, on the contrary, a wide gap in the succession of the beds 
represented by the absence of the Old Red Sandstone in this district. 
I feel satistied that in this district a whole geological formation 
—that of the Old Red Sandstone—which in the adjoining districts 
* Explanation to sheets 192 & 199, p. 8. 
