151 
In the bluff on the south side of the stream, as pre- 
viously stated, the rock appears more like a trap ash of 
a reddish-brown colour, and exhibits traces of bedding and 
white lines like carbonate of lime. Immediately adjoining 
trap ash, and on its rise, occurs the coarse breccia composed of 
fine-grained siliceous rocks, cemented together with quartz, 
and like a permian breccia ; but although the beds are near 
together, there was not evidence to show whether the trap 
ash gradually passed into the breccia or intruded through 
it, still the breccia appeared to dip in the same direction, 
but at a much less angle, namely, 25° to a little west of 
north. This is a very interesting fact to prove ; for if the 
rock graduates into the breccia, it would appear to be of 
permian age, and most probably a melaphyr, but if it is 
intrusive, as the evidence on the whole appears to prove, 
all we can say is that it is of later date. 
This breccia is composed of angular pieces of a fine sili- 
ceous stone, of a pink colour, more resembling quartzite than 
anything else cemented together by small quartz crystals, 
and containing minute quantities of protoxide of manganese. 
The form of the fragments is very like that of the rocks 
in the permian breccia of Rougham Point, near the moun- 
tain limestone of Humfray Head, and there consisting for 
the most part of the neighbouring mountain limestone, but 
no limestone has yet been met with in the Gleaston breccia 
as might have been reasonably expected; and the pink 
quartzite is a rock hitherto unknown in the district. The 
permian breccia so far as my experience goes, although some- 
times containing volcanic ash are composed of the rocks no w 
found in the neighbourhood where they occur, and nearly 
always vary with the older geological rocks of the district. 
The composition of the Gleaston breccia makes me hesitate 
in designating it as permian as it may be some rock altered 
by the dyke. 
The rock in its best state of preservation is remarkably 
