THE
ESSEX NATURALIST:
BEING THE
Journal of the Essex Field Club,
(VOLUME XII.)
GEOLOGICAL NOTES ON THE NEW RESER-
VOIRS IN THE VALLEY OF THE LEA, NEAR
WALTHAMSTOW, ESSEX.
By T. V. HOLMES, F.G.S., F. Anthrop-Inst. ; Vice-President E.F.C.
[Received April 25th, 1901.]
These reservoirs, the excavations for which have been in
progress for more than a year and are still proceeding, are in the
Valley of the Lea west of Walthamstow and east of Tottenham,
and are being executed for the East London Water Company
by Messrs. S. Pearson and Sons. The more northerly, which
will be known as the Banbury Reservoir, occupies the marsh
between Higham Hill and the outfall of the Ching ; the more
southerly is south west of Higham Hill and east of Stonebridge
Lock. The words "Mitchley Marsh" appear on the Ordnance
Map (6in. to the mile) towards its southern end. Two older
reservoirs, known as the Low and High Maynard, lie east or
south-east of this new "Lockwood" Reservoir. All are north
of the road connecting Tottenham Hale and Blackhorse Road
railway stations. (See Plan).
Before touching upon the nature of the beds seen in the
reservoir excavations, it may be useful to say a few words on the
general geological structure of the locality. The oldest forma-
tion visible is the London Clay, which underlies the marshes in
the Lea Valley and appears in the higher ground on each side.
Patches of gravel and loam, fragments of old river deposits
formed when the existing streams, not having eroded their