THE LOWER CARBONIFEROUS BEDS OF HOOK. 
147 
save by a few unimportant faults, which do not prevent a correct 
estimate being formed of the thickness of the entire series. The 
beds are conformable throughout, and admit of being divided into 
five distinct groups, which I propose to describe in succession, com¬ 
mencing with the oldest beds of red conglomerate, which rest on 
the Silurian slates unconformably. 
1. OLD RED SANDSTONE AND CONGLOMERATE. 
The Old Red Sandstone and conglomerate of this district rest un¬ 
conformably on the nearly vertical beds of Silurian slates, the line of 
junction extending in nearly a straight line from Carnivan Head 
on the east, to a point half-way between Harry loch and Templetown 
church on the west. The nature of the junction between the con¬ 
glomerate and slate is well shown in the face of the cliff at Carnivan 
Head. 
The beds of slate are nearly vertical, and the Red Sandstone 
and conglomerate beds are inclined at an angle of 10° to the horizon. 
I propose to place, provisionally, the uppermost limit of these beds 
at a line drawn from the rocks north of Sandeel.Bay on the east, to 
the boundary of the townlands of Templetown and Houseland on 
the harbour, or west side. My reasons for fixing on this boundary 
will be explained in the next section. Within the limits I have as¬ 
signed, the rocks consist of slightly inclined beds of massive red con¬ 
glomerate, alternating with layers of red sandstone and red shale. 
They are quite destitute of fossils; and may be considered as typical 
beds of the Old Red Sandstone of the south-east of Ireland. I have 
measured the thickness of these beds in a variety of ways, and esti¬ 
mate it at 1150 feet. The sea must have been shallow during the depo¬ 
sition of these beds, as it is not possible to conceive any action save 
that of coast waves capable of forming such masses of rolled shingle, 
alternating as it does with sands and mud, tinged with peroxide of 
iron, evidently introduced by currents of a less violent character 
than those which laid down the rolled shingle of the sea beaches, 
which formed the materials out of which the red sandstone conglo¬ 
merate was elaborated. 
2. PLANT BEDS. 
The uppermost portion of the sandstones and conglomerates 
consists of alternating beds of red conglomerate, red micaceous sand- 
