File:The Quarterly journal of the Geological Society of London (12711584245).jpg

490
PROCEEDINGS OF THE GEOLOGICAL SOCIETY. .May 2,
to say. There are, however, mdications tending to throw the balance
of evidence on the side of the latter supposition, and this view is in
Fig. 9. — Section of the Warp-Drift, resting on Great Oolite, at
Compton Hill.
a. Warp-Drift ; of brown loam, varying in thickness from 1 to 4 feet ; and con-
taining a few pebbles probably derived from Northern Drift.
b. Thin-bedded sandy oolite ; forming lower portion of the Great Oolite forma-
tion.
accordance with the fact, that the soils vary rapidly in composition
and appearance upon every change in the substratum.
Dr. Voelcker has also arrived at the same conclusion, founded
upon analyses of the soils taken from several formations in the neigh-
bourhood of Cirencester. Some of the results he has kindly placed
at my disposal, and they will be found appended to this paper.
Estuarine Deposits. — The estuarine strata of the valleys which
surround the hilly district on the north and east sides may be di-
stinguished from those of the Northern Drift by the predominance of
detritus derived from the waste of local oolitic rocks, either broken
up and stratified by the action of the estuarine sea itself, or carried
down the slopes from the higher grounds by brooks. These accu-
mulations occupy only the valleys and plains, but their stratification
cannot be referred to the agency of the present streams.
Fragments of rocks which have been transported from a distance
are generally to be found scattered through the estuarine gravels, but
their presence will readily be accounted for when it is recollected that
the greater portion of the country was overspread by Northern Drift
previous to the estuarine period, and from this deposit these far-
fetched pebbles have, in all probability, been derived. Indeed, there
is reason for concluding that during this *' second stationary" period
a considerable portion of pre\iously formed Northern Drift was re-
stratified, and may in this sense be considered estuarine. Accumu-
lations referable to the estuarine period occur in the Vale of Bourton,
at Paxford, and along the valleys of the Evenlode and Stroud, and
overspreading the flat districts of the Oxford Clay to the south of
Cirencester. In this last-mentioned neighbourhood, along with the
oolitic gravel, chalk-flints occur, derived from the waste of the chalk-
escarpments to the south and east. Everywhere these gravels con-
tain remains of extinct mammalia, and in Stroud Valley they are re-
markably numerous * .

• Some of these remains are in the possession of Mr. Carpenter, of Caincross ;
  

and a tusk of a fossU elephant in the Museum of the Royal Agricultural College,