ALLUVIAL AND OTHER RECENT DEPOSITS AT FELSTEAD.
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a land-shell—Helix arbustorum—common in two places as a fossil,
but I believe locally extinct.3
The immense accumulation of clay resulting from slow deposition,
and even the few changes we can note in the fauna, point to a great
antiquity for the alluvium. We are in no position to measure this
by years. All that we can certainly affirm is that the historical
period, say of a thousand years, has but little altered its appearance.
The river is a parish boundary now, and it was so in Anglo-Saxon
times ; the roads and paths skirt the alluvium at places, and it is
but reasonable to suppose that they have done so from the time that
the alluvial bed was a soft one, and that, therefore, the configuration
of the bed since that early date has not changed. The fords are those
of the Saxons—hard gravel now as then where the stream runs fleet.
"Hartford-end" they tell us means "Hard-fold." These are the
ancient barriers of glacial gravel that time or the ripple of the stream,
or the winter's flood or frost, do not wear appreciably : the slightest
choking here would convert the back water into a morass or even
into a lake.
Moreover, in going into this question of historical change, we can
refer to the Roman road. There are places (notably near Stebbing
Ford) where the fields on either side slope towards this road, and
the soil is therefore washed down in that direction. The amount of
accumulation of post-Roman clay there does not generally exceed a
foot, for Roman remains occur at that depth and not deeper, so far
as I am aware. These considerations, when applied as a measure of
denudation or accumulation, lead us to believe that a thousand years
is a small proportion of the time occupied in the formation of the
alluvium.
The study of this bed certainly helps us to a conception of the
long period which has elapsed since Glacial times. Even if on
examination it be found that the alluvium is fossiliferous to its base,
we know that however great its antiquity may be, we have not there
a continuous record from Glacial times, for we must allow a vast
period of time for the elevation of the area from the glacial sea, and
the advent of plants and animals which could not have lived even
on islands under Arctic conditions. From whence came these shells,
the early inhabitants of the valley ? Here again we are brought face
'Mr. W. H. Dalton, F.G.S., who very kindly looked through these sheets before they were
sent to the press, says, referring to the above-named three species of mollusca, "If my memory
serves me, I have found all these living too near Felstead to be called 'locally extinct.'" Nega-
tive evidence is always very unsatisfactory, and we shall therefore be glad to have any facts our
conchological readers may be able to bring forward bearing on the above remarks.—Ed.
E 2