229 
Geological Relations of the East of Ireland \ 
seem conformable to what has been already stated. In Talbot bay 
is a third bed, which nearly occupies the inlet, forming the middle 
and part of the sides, being flanked on either hand by greenstone. 
This bed is about sixty yards wide, and in the eastern quarter it 
consists principally of clay slate, frequently traversed by small 
veins and filaments of calcareous spar. This rock sometimes con- 
tains also small imbedded portions of limestone and pebbles of 
differently coloured slate, and it merges into greywacke slate, being 
interstratified in thin beds with fine grained greywacke. In the 
western quarter, these rocks are joined by, and in immediate con- 
tact with a perfect clay slate conglomerate, in which the fragments 
are not in general much larger than walnuts or hazel nuts, but some 
of them are nearly as great as the head. This coarse clay slate 
conglomerate is succeeded on the west by a similar rock of finer 
grain, or by greywacke, and greywacke slate, but to the west of this 
we find a fine grained greenstone conglomerate. These latter rocks 
form massy strata, four or five feet thick. There is an evident 
affinity and intermixture between the greenstone conglomerate and 
fine grained greywacke, so that in some places these rocks partly 
interchange characters. All these beds range 20° north of west 
and south of east, and dip 65° toward the west of south. 
The greenstone conglomerate merges, toward the west, into com- 
pact greenstone, containing nodules or nuts of calcareous spar ; and 
hence near the surface, this rock has in some places a vesicular 
aspect, from the decomposition of the carbonate of lime. It passes 
into greenstone, nearly compact, and this into greenstone porphyry. 
Farther west we encounter another, but smaller, bed of clay slate in 
an inlet from the sea, which is succeeded by compact greenstone ; 
and in the last inlet to the west which occurs on the south side of 
the island, we find another bed of clay slate, accompanied by clay 
