GRACE : THE GLACIAL GEOLOGY OF FURNESS. 419 
probably still filled with its glacier, extending along the western 
side of the estuary. This would account for the entire absence of 
evidence on that side. 
Numerous remains of sandbanks and what appear to be terraces 
are to be found at 100 feet all the way from Askham to Woodland 
Church, but the growth of vegetation and Post-Glacial alterations 
have made some of them very difficult to recognise. A large delta 
occurs in the Woodland valley bottom, near Bridge End, which does 
not reach above the 100 feet contour, and a delta-like deposit rear 
Woodland Church seems to belong to this stage. A well marked 
channel with thick, current bedded sandy deposits runs from Askham 
southwards to Park Farm. 
The overflow for the 100 feet lake was a well-marked channel on 
the eastern side of Park Knotts leading directly into the Goldmire 
Valley and by Mill Wood. This is a much larger channel than those 
previously described, and was probably in use for a longer period. 
The railway cutting near Park Mine has considerably modified the 
shape of the valley there, but the original height of the col (93 feet) 
confirms our estimate of the level of the water. 
{d) The Final Stage of the Lake. 
The last stage of the lake to be represented by present deposits 
would be reached when the Irish Sea Ice retreated as far as Walney, 
and the existing channel between that island and the mainland may 
have been the last drainage channel of the Duddon before the sea was 
entirely open. Walney Island contains no rocks older than drift 
down to a level of 80 feet below O.D., and, consequently, is entirely 
of Glacial and Post-Glacial origin. 
The only published reference to these glacial lakes in the Duddon 
Estuary appears to be by Mr. B. Smith in his paper on the Glaciation 
of Black Combe.* 
In conclusion, we beg to acknowledge the assistance and advice 
of Mr. Bernard Smith and Dr. Gilligan, whilst we have been preparing 
this paper, and also the help, on several points, of Prof. P. F. Kendall, 
whose papers on Glacial Geology have been a continual inspiration 
during the twelve years we have been working at the geology of 
Furness. 
* Quart. Joum. Geol. Soc, Vol. LXVIII. (1912), p. 420. 
