28 G. H. Rinahan—Geology of Connaught and Ulster. 
Curtew Movnrars Section, Cos. Mayo 
AND RoscoMMON. 
F 
300 feet. Eurite, tuff, etc. 
_ ———$$—$  —_—__—_— 
Purple, red and green 
6 sandstones, flags, 
oO 
a and sandy shales. 
(<>) 
i=) 
Lo) 
D}.. 
eA Green sandstones, 
3 and shales, with a 
S few fossiliferous 
S Limestones, 
—s 
C =smesese see ee ee 
xx |Fossils, 
3] REGIS Uae ere ee, Limestone, fossils. 
Red and purple con- 
glomerates, sand- 
stones and sandy 
shales. 
1500 ft. 
pa 
UNCONFORMABILITY. 
a7. OG WA Va OA 7 \Cambro-Silurian or 
Cambrian. 
The rocks from A to C 
occur in a continuous 
section; those from C to 
D are not as well ex- 
posed, but sufficient of 
them are seen to show 
that from B to D they 
are about 4,000 feet 
thick ; while the thick- 
ness from D to F had 
to be estimated. The 
eurites and tuffs (Hi to F) 
are of various thick- 
nesses, but on an average 
they seem to be about 
300 feet thick. Above 
the eurites there seem 
to be no rocks, or only 
a very slight thickness 
of rocks in the Curlew 
Mountain district; but 
in the Fintona district 
above this zone there are 
massive conglomerates, 
sandstone and _ sandy 
shales associated with 
some beds of limestone. 
The limestones may be 
of limited extent, as they 
were only remarked in 
one district. 
As to the age of these 
rocks. Those below the 
unconformability at A, 
are metamorphosed and 
have been called Upper 
Silurians and Felstones. 
The latter name is so far 
correct, in that some of 
the rocks are granulites 
(metamorphic felstone), 
rocks which many Petro- 
logists include among 
the felstones. 
It is, however, per- 
fectly incorrect to call 
any of them Upper Silu- 
rians; as they were 
metamorphosed, rup- 
tured, upturned, and 
