38 THE ESSEX NATURALIST
vertically through them. Here and there the silt was lamin-
ated and in places it alternated with seams of peat. The base
of the deposit dropped to below the excavation level at the
southern end of the cutting.
The silt was followed by about 4ft. of peat which appeared
to consist of two distinct but vertically continuous beds and
these in turn were capped by the usual marsh clay. At the
extreme north of the section the peat was observed to thin out.
The silt deposit was lithologically unlike the beds of the
Nazeing Stage already encountered in these workings. The
complete absence of Charophyte marls and the actual or virtual
absence of molluscs from the samples examined demonstrated
that the beds of the "M" sub-stage were not present. At the
same time the position of the silts indicated that they were of
the Nazeing Stage. Although they do not agree in appearance
with those beds in the type area, the author confidently corre-
lates them with the first, or "D," sub-stage at Nazeing.
Marked differences may be expected in localities which are
some ten miles apart.
The measured section is given in Plate 4. It demonstrates
two striking facts :—
1. As in other localities already mentioned, the deposits of the
"D" sub-stage and the succeeding peats are localized with-
in an incised channel.
2. This appears to be a continuation in time of the deep, late
glacial channel already reported and which has been in-
cluded in the section in Plate 4. This point will be referred
to below.
b. The excavation to the east. For engineering reasons it
was necessary for this area to be cleared of silt and peat and for
the underlying gravel to be exposed. Thus it was easy to trace
the direction of the depression occupied by the silts just
described. This was found in the south-west corner of the ex-
cavation as indicated in Fig. 1. The base of this depression
was at approximately 17.0 O.D., that is, very little below the
excavation level of the trench described in the last section.
Samples of the silts from this area were taken for washing.
One piece was so rich in beetle remains of several species and
individuals that it must be assumed to have contained an owl