NAZEING STAGE (PLEISTOCENE) 41
4. Summary.
The following facts have emerged from this investigation :—
a. The deposits of the Nazeing Stage have been recognized as
far south as Walthamstow. Both sub-stages have been
found.
b. The lower, or "D", sub-stage retains its marly character
probably as far as Waltham Abbey, but in the south of the
area it becomes silty with much plant matter.
c. The upper, or "M", sub-stage retains its lithological and
Palaeontological features at least as far as Edmonton, but
it may develop a marginal silty facies.
d. The two sub-stages are relatively independent of each other
and each is found to occupy an incised depression or
"channel". The peat which follows the deposits also
appears to be localized within the "channel".
e. In one area there appears to have been continuous sedimen-
tation from late glacial times, the deposits of the Nazeing
Stage lying within a deep channel.
5. The vice-comital distribution of sites.
Learned societies of various counties have different methods
of recording their data. While some accept the existing admin-
istrative county boundaries, others still adopt the system of
vice-counties established by H. C. Watson in the last century.
In the middle Lea Valley three counties are involved so that
difficulties are presented by two facts. In the first place there
is some uncertainty as to the exact boundaries in Watson's
time and the matter is still sub judice. The second difficulty
is caused by the difference which exists, here and there, be-
tween the old and new boundaries. For this reason details are
given in Table 2 of the distribution of sites referred to in this
paper.