PROCEEDINGS 
OF THE 
GEOLOGICAL AND POLYTECHNIC SOCIETY 
©f ttje 512aest Killing of ¥orfts!}irc, 
AT THE FORTY-FIFTH MEETING, HELD IN THE 
CUTLER'S HALL, SHEFFIELD, ON WEDNESDAY, JULY 30TH, 1856, 
AT TWELVE O'CLOCK AT NOON. 
Thomas Dunn, Esq., in the Chair. 
The following noblemen and gentlemen were elected 
members : — 
His Grace the Duke of Norfolk. 
His Grace the Duke of Leeds. 
The Eight Hon. Lord Wharncliffe. 
Viscount Goderich, M.P. 
E. E. Sanderson, Esq., Sheffield. 
G. S. Beecroft, Esq., Ahhey House, 
. Kirkstall. 
J. 0. Butler, Esq., Kirkstall. 
W. Chadwick, Esq., Arksey, Doncaster. 
T. P. Teale, Esq., F.L.S., Leeds. 
The Chairman called upon Mr. Sorby, of Sheffield, 
to read the first paper : — 
ON THE ORIGIN OF THE CLEVELAND HILL IRONSTONE. 
BY H. C. SORBY, ESQ., F.G.S. 
The investigation of the circumstances that have given 
rise to the various rocks that are met with, constitutes a 
branch of Geology of considerable interest. It has too 
frequently been supposed that stratified rocks were accumu- 
lated in a form far more like what they are now, than is 
warranted by a more careful enquiry ; and this has, in many 
cases, led to the conclusion that the conditions under which 
o o 
