PEBBLES DRIFTED FROM SHIPSTON TO OXFORD. 
2,51 
The diluvian current thus impelled into the Bay of Shipston, 
from the north-east, appears to have continued its course onwards 
beyond the head of this bay, near Moreton in the Marsh, (see Plate 
XXVII.) bursting in over the lowest point of depression of the great 
escarpment of the limestone ; and being deflected thence south-east¬ 
wards by the elevated ridge of Stow in the Wold, to have gone for¬ 
ward along the line of the vale of the Evenlode by Charlbury, till 
it joined that of the Thames at Ensham, five miles north-west of 
Oxford. 
This hypothesis affords the most satisfactory explanation of the 
origin of the great deposits of granular quartzose pebbles, which not 
only cover irregularly the lower regions of the valley of the Even- 
lode, but are scattered abundantly over the surface of the oolite 
strata, where they rise to a considerable height, and form table-lands 
on both sides that valley along its whole extent. It also accounts for 
the accumulation of beds of similar pebbles on the west and south of 
Oxford, upon the insulated and almost conical summit of Wytham 
Hill, and the ridge of Bagley Wood, by their position exactly op¬ 
posite the mouth of the vale of the Evenlode, at its confluence with 
that of the Thames, at the very point on which the driftings eva¬ 
cuated from the former valley would be collected*. Being thus 
introduced within the escarpment of the oolite, and having passed 
along the line of the Evenlode into the country round Oxford, 
these quartzose pebbles have been forced onwards, and mixed up 
* Near this same point, pebbles of clear rock crystal occur scattered over the sur¬ 
face at Ensham Heath, and are applied to the purposes of jewellery, like the Bagshot 
Heath diamonds, as they are commonly called, being merely small pebbles of crystallized 
quartz. 
K K 2 
mm 
■ 
