TRANSACTIONS OF SECILION C. 543 
the Chalk hills between Newmarket and Royston, it only travelled thence to the 
south-east for about half that distance. In this region the Boulder Clay is chalky 
near the escarpment, while beyond the outcrop of the London Clay it is mainly 
composed of detritus from that formation. oo. ; 
Along the basin of the Ouse, where its matrix is largely Oxfordian, the ice to 
which it was due advanced much further, to Buckingham and beyond, as it also 
did along that of the Nene, in the direction of Northampton. On the contrary, 
the high land near the head waters of the Welland obstructed the ice-tlow, so that 
but little Boulder Clay seems to have found its way into the area comprised in sheet 53 
of the Ordnance map. ‘The greater part of sheet 63, however, is covered by it, and 
it there reaches an elevation of 730 feet above the sea level. Much of the 
Boulder Olay of this region, in the author’s opinion, was due to the ice-stream of 
the Trent Valley having been piled up upon the high land to the east of Leicester 
by the pressure of ice descending from the Pennines. 
It seems probable that the whole of the low-lying region between the Lincoln- 
shire Wolds and the Pennines was filled with ice during the period of maximum 
glaciation. It is not physically possible that any considerable thickness of ice 
could have existed on one side only of the Lincolnshire ridge, which does not 
often exceed an elevation of about 200 feet above the lower ground adjoining it. 
The author hopes to make the ultimate source of the chalky Boulder Clay ice the 
subject of a future paper. The prevalence of Carboniferous dédris in the East 
Anglian region seems to indicate, however, that a part of it at least was of 
Pennine origin ; another part may have been due to an overflow from the North 
Sea across the lowest part of the Chalk Wolds, and the ice may also have been 
reinforced by the abundant precipitation to which this district was subject during 
the Glacial period ; the moisture-bearing cyclonic disturbances from the Atlantic, 
to which the enormous accumulation of ice in the Baltic region was due, must 
have passed near the eastern counties of England. There is no evidence to show 
that any considerable amount of ice entered East Anglia through the Wash gap, 
all the facts known to the author appearing to point in an opposite direction. 
3. On a Great Depth of Drift in the Valley of the Stour. 
By W. Wuiraker, /.2.S. 
Several cases of great irregularities in the thickness of the Drift have been 
shown by borings in Suffolk, where the existence of deep channels filled with Drift 
has been practically proved, as also in the neighbouring counties of Essex and 
Norfolk. In some cases these channels cannot be shown on the map, the Glacial 
Drift being hidden by deposits of later age, and this is markedly the case in the 
upper part of the valley of the Cam, where at one place (Newport) the Drift has 
been pierced to the depth of 340 feet: without reaching the bottom. 
In Suffolk the greatest amount of Drift recorded is at Brettenham Park, where 
apparently a thickness of 312 feet has been found. But this and all other records 
in Kast Anglia are now put into the shade by the result of a boring near Glems- 
ford railway station. This is ata low level in the valley of the Stour, in the tract 
formed by the sand and gravel that crops out from beneath the Boulder Clay of the 
higher ground. Here one would have expected, perhaps, some 50 feet of Drift; 
but certainly not more than 100. No less than 477 feet have been passed through, 
before reaching the Chalk. 
The gravel and sand that form the surface reached to a depth of 51 feet, as 
might have been expected; but then the unexpected occurred, no Jess than 
228 feet of boulder clay (partly sandy) having been found, with a mass of sand and 
clayey sand beneath. 
We seem here then again to have evidence of a very deep Drift-filled channel. 
A well in the village, at a higher level, has reached Chalk after passing through 
120 feet of Drift; so the channel does not reach far northward, nor does it reach to 
Foxearth, in Essex, about a mile to the south, where there is a still less thickness 
of Drift. As to its direction or extent, however, we can say little as yet. 
