298 TATE: THE YORKSHIRE BOULDER COMMITTEE. 
breccia, felsitic tuff, olivine basalt, porphyrite, andesitic breccia, 
vesicular lava, carboniferous limestone, Flamborough flint, and 
Yorkshire fossiliferous lias—all of which are rocks foreign to the 
district ; many are polished or striated, and so tell their own story. 
In addition to these are several (Nos. 8, 13, 30, 31, 39) non-British 
rocks—red and grey granites, gneissose granites, felspar porphyries— 
having a somewhat Norwegian aspect both in the hand specimens 
and in microscopic sections ; these will require further comparison 
with parent rocks before they can be finally identified 
Whence came this glacial detritus, and by what route? To the 
west this area is bounded by higher ground, yielding no trace of glacial 
débris ; east and north-east we have low-lying ground continuous 
with the valley of the Calder. However, that the glacial drift 
under consideration is not an offshoot of the Calder Valley deposits 
recorded last year may be inferred from the absence of Buttermere 
granophyres, Yewdale breccias, and Eskdale granites, the charac- 
teristic rocks of that dispersion. The solitary examples of Ennerdale 
syenite (14) and of Borrowdale plumbage (47) nevertheless may have 
been borne down that valley. When traced back to their original 
sources the evidence of far-transported stones points to the Lake 
Country as being the centre of dispersion for the ice-drainage of the 
North of England during the glacial episode. With the exception 
of the non-British stones, which came by the Scandinavian glacier, 
all the crystalline rocks recorded have most likely been brought to 
their present resting-place by the Shap-bearing ice-stream from the 
north-east corner of the Lake District, by way of Stainmoor and the 
Yorkshire Lune, to Teesdale, thence, deflected by the Cleveland 
hills, into the Vale of York, and the low-lying valley (50-100 ft.) 
traversed by the York and North Midland Railway may indicate the 
line of further dispersal. If so, we have here a prolongation of the 
extensive and well-known deposits of that central valley, representing 
the period of maximum expansion. 
The exploration of the glacial geology of the eastern portion of 
the county, initiated last year by this Committee, is being prosecuted 
methodically by the East Riding Boulder Committee, under the 
excellent guidance of their honorary secretary, Mr. jew. Stather, 
‘.G.S. Several erratics are recorded herewith, and a fuller report 
may be expected next year. 
With a view to stimulate general interest in the preservation of 
Yorkshire ice-borne relics, the Committee have had one of the Shap 
granite boulders reported last year (No. 3) removed from Laithkirk, 
in Lunedale, to the grounds fronting the Yorkshire College, where it 
is open to public inspection. They thankfully acknowledge the 
Naturalist, — 
