160 
JOURNAL OF THE GEOLOGICAL SOCIETY OF DUBLIN. 
the grit and slate, but, as the period went on, they become more 
hornblendic till you come to the uppermost bed on the south of the 
island, where they are hornblendic felstone, nearly approaching a 
greenstone. These are in some places conformable, in others not, 
as seen by the sections (Figs. 3, 4, 5, and 6, which are all sections 
taken at different places of the same mass of trap) at the junction with 
the grits and slates. They fused slightly with the blow-pipe. After 
Fig. 3. 
1 
fit- 5 c 
West end of Tabular Trap, 
looking east. 
a, Slate. &, Altered slate, 
c, Felspathic greenstone. 
Fig. 4. 
Fig. 6. 
Looking east; Slate dipping west. Further east, looking west. 
a, Trap. &, Slate. a and c, Trap. 6, Slate. d, Slate. 
this period the greenstone dykes seem to have been formed. The 
greenstones are a much darker green than those in the Old Red 
Sandstone at Cod Head and the Dursey; the dykes are very ashy- 
looking, or flaky, but generally have here and there through them 
compact portions, or end in a compact boss. The conformable 
felstones are either bluish or white, with crystals of felspar widely 
disseminated through them. The ashes have also crystals of felspar, 
but none of them become a regular porphyry, as seen in the Kerry 
traps. The age of the felstone dykes is hard to be fixed, as they 
only appear on the coast, and in no place were they found in con¬ 
tact with the greenstone dykes. 
