12 
“Notes on some Superficial Deposits at Great Orme’s 
Head, and the Period of its Elevation,” by It. D. Darbi- 
shire, B.A., F.G.S. 
After referring to Professor Ramsay’s exposition of suc- 
cessive glacial periods in North Wales and its elevation; 
( Quarterly Journal Geol. Soc. viii., and Old Glaciers of 
Switzerland and N. Wales, 1860) to a paper by Mr. Binney, 
F.R.S., on “the Drift Deposits found about Llandudno” 
{Geol. Soc. Trans. Manchester, April, 1861), and a paper by 
Mr. Bonney “On Traces of Glacial Action near Llandudno” 
Geol. Magazine iv., July, 1867), the author shortly described 
the configuration of the Head and the Llandudno Isthmus. 
He supposed the superficial outline of the Head to be due 
to marine denudation, possibly aided at some early period by 
the friction of floating icebergs, but in the last instance and 
ever since its first emergence to long continued and extremely 
tranquil elevation and concurrent ssecular subaerial degra- 
dation and deposit. The isthmus, he described as ancient 
sea bottom, gradually elevated and denuded in the process 
by current or tide wash, and then augmented by beach 
accumulation and blown sand. 
Detailed notes as to the superficial formations were then 
read as follows : 
I. — Marine Formations. 
(1) Yellow cherty clay in Gwydfyd Valley, as described 
by Mr. Maw, F.G.S., Geol. Mag. ii., 1861. 
(2) Glacial and boulder clays of a later age : 
(а) Tenacious dark blue clay, full of small pebbles of * 
dark slaty rock, at the foot of the western cliff 
of the isthmus and on the beach, as described 
by Mr. Bonney, Geol. Mag. iv., p. 292. 
(б) Close greyish olive coloured rather sandy clay, with 
rounded stones, in similar situations (possibly a 
variation of {a.) 
