F. R. Cowper Reed—Coastal Features, Co. Waterford. 17 
of most of the felspar; more commonly lath-shaped plagioclases and 
in many cases prisms and granules of augite project into the hollows." 
This shows that the lavas as they issued from the volcanic pipes 
consisted of viscous and partially crystallized material. 
In hand specimens the actual base of a flow containing pipe- 
amygdales for a distance of from a quarter of an inch up to two inches 
contains small vesicles, or as one may almost term them ‘undeveloped 
pipes.’ Above this, where the temperature of the rock would have 
been greater, the lava is crowded with tubular vesicles which run into 
one another as they are followed upwards and give rise to a branching 
structure. After these terminate we may find elongated or irregular 
vesicles, evidently ‘pipes’ that have risen bodily through the lava and 
have become more or less modified by movement and temperature. 
Sometimes similar amygdales are found above these, but as a rule 
at a distance of a few feet above the base of the flow the normal rock, 
vesicular or compact, is found. 
Commonly the pipes are arranged perpendicularly to the base of the 
flow, but sometimes, and this 1s commonly the case in Barkly East, 
the amygdales are much inclined. Deviations up to 60 degrees 
from the normal are found, indicating motion of the lava during their 
formation. 
In some parts of the Drakensberg pipe-amygdaloids are very 
abundant; close to the town of Barkly East there are over a dozen 
horizons within a thickness of not more than 200 feet of rock. 
An interesting parallel to the way in which I have supposed the 
pipe-amygdales to have been formed is afforded by some experiments 
of Messrs. J. ’Anson & E. A. Parkhurst.? Bubbles of carbonic acid 
gas carrying with them some sulphuric acid were allowed to rise 
through a solution of an alkaline silicate, and formed in their upward 
passage peculiar delicate, irregular, and branching tubules of colloidal 
silica much resembling corals. 
V.—Nores on some Coastat Fratures 1n Co. WArERFORD. 
I. Fornacur Srranp. 
By F. R. Cowrer Reep, M.A., F.G.S. 
fJ\HE occurrence of ‘ submerged forests’ on the coast of co. Waterford 
has long been known, though no mention of them was made in 
the Survey Memoir published in 1865. The more recent discovery 
of pre-glacial beaches and raised wave-cut rock-platforms along the 
south coast of Ireland between Baltimore and Carnsore Point? has 
thrown still further light on Post-Tertiary movements of the land- 
margin; and accordingly some new observations on these phenomena 
in a hitherto unmarked locality may be of interest. 
On the west side of the broad mouth of the River Suir there is an 
unfrequented bay bounded by Creadan Head on the south and 
Ann. Rep. Geol. Commission for 1904, p. 134. 
Min. Mag., vol. v (1884), p. 34. 
Muft & Wright: Gror. Mac., Dec. IV, Vol. X (1903), p. 501; Sc. Proc. 
Roy. Dublin Soe., n.s., vol. x (1904), pp. 250- 324 ; We Geology of Country around 
Cork”’ (Mem. Geol. Sury. Ireland, 1905, p. 36 et seq.) « 
DECADE V.—VOL. IV.—NO. I. 2 
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