A SKETCH OF THE GEOLOGY
149
tional reservoirs in them during that period. With
much variation in details, these sections usually
disclose clayey loam at the surface, then more
or less peat and shell-marl, then sand and gravel
at the bottom, of an excavation 7 or S feet
deep. Among the mammalian remains found in
these deposits in 1868, Dr. H. Woodward (Trans.
Essex Field Club, vol. iii. pp. 1-29) mentions those
of the wolf, fox, beaver, horse, wild-boar, reindeer,
gigantic ox (Bos primigenius), and elk.
In short, the London Clay underlies all the
other formations mentioned from the Bagshot
outlier at High Beach to the recent alluvium of
the Lea and Roding. At one time Bagshot Beds
covered the whole of the area of Epping Forest
and extended far beyond it to the east and west.
Then much later, in post-Pliocene times, came the
deposition of the Westleton Shingle, and, some-
what later still, of the Glacial Gravel and Boulder
Clay. After the close of the Glacial Period the
present river systems came into being, and the
Lea, Roding, and Thames cut their way through
the deposits already mentioned, deepening and
widening their valleys as they did so, and leaving
behind them the various beds of gravel, peaty
matter and loam, which are the most recent
of all.
While much planing down of the then existing
surface must have taken place through the action
of the sea, during the deposition of the Westleton
Shingle, and through the agency of ice in some
form during that of the deposits of the Glacial
Period, the present scenery of Epping Forest can
scarcely be said to owe anything to those distant
and remote influences. For the sculpturing of
the surface which has given us the present dis-
tribution of hill and valley is due to the action of
rain and rivers much more recently, to agencies
still at work, and which may be said to have
originated with the present river system in post-
Glacial times.