NOTE ON SECTIONS IN THE LEA VALLEY,
111
Towards the Lea the peat bed became laterally simply a
very dark brown clay band as the quantity of decayed vegetable
matter diminished, and the section at this side consisted only of
the clayey alluvium resting on the gravel. The consistency was
fairly stiff and the colour light at surface, with the above-named
dark band at the bottom. The loam is in some parts laminated
with parallel bands of light grey three or four inches thick, and
has the remains of numerous roots from former growth above.
Traces of old channels occur as shown on annexed section. The
shells are mostly broken, but are probably similar to those
described by Dr. H. Woodward in vol. iii. of the Transactions of
the Essex Field Club as found in the old reservoir in 1869.
In Whitaker's Geology of London (vol. ii., p. 41) Mr. W. B.
Bryan has given the depth to the London Clay at one of the
adjacent reservoirs as 22ft. 6in. The six-inch Ordnance Map
gives B.M. 23ft. bin. near the south end and 25ft. 2in. near the
north.
[In a small quantity of material sent to me by Mr. William
Cole, the few species of shells to be made out are :—
Vitrea cellaria Planorbis contortus
Helicigona arbustorum Bythinia tentaculata
Helix nemoralis Valvata piscinalis
Limnaea auricularia Valvata cristata
Limnaea stagnalis Neritina fluviatilis
Planorbis albus Sphaerium corneum
All these species have already been recorded for the Lea
Valley deposits : see Messrs. Kennard and Woodward's paper
in the present part of the Essex Nat., and the accompanying
table.—Wilfred Mark Webb.]