THE " RED HILLS " OF CANVEY ISLAND. 139
The mound rises to a height of 5ft. above the level of the
plain that separates it from the Estuary of the Thames and
Thorny Creek and is bisected on a N—S. line by Blackmore
Avenue. The highest point attains a level approximately 6ins.
below the high tide1 level of the Estuary at this point, and is
situated 380 yards from the shore to the south and 250 yards
from the creek to the south-west. Before the date of the erection
of the first sea-wall by the Dutch the hill must have been subject
to inundation at times of spring-tide.
In its geographical situation and in the general character of
the sub-soil and associated objects, the Canvey sites correspond
with the Red-hills of Essex, investigated by the Exploration
Committee in 1906-7.
" 'Red-hills,' " they say, "are low flat mounds of variable
"outline standing only a few feet above the level of the marshes
"on which they are found, and in external appearance they have
"little to distinguish them from other marsh mounds of a flat
"description. The distinguishing feature is the material of
"which they are formed, this being a compact mass of burnt
"earth of varying shades, red in colour, of a fine loose texture,
and containing many pieces of burnt clay, which have been
"definitely shaped, though always in a fragmentary condition.
.....All are situated on or near the belt of land known
"as the edge of the alluvium which marks the old line between
"high and low water."
Various hypotheses have been advanced to account for the
vast accumulation of burnt earth and associated objects on these
special areas, but the Committee concluded that little evidence
has been gained to support any of the various surmises con-
cerning the nature of the industry centred thereon. It is
generally agreed, however, that domestic, relics found on the sites
explored by the Committee occur in such insignificant quantity
and in such fragmentary condition as to preclude the possibility
that the mounds in question were occupied sites. The pottery
found was considered to indicate a date not later than the first
century A.D. Pottery of better quality, it was pointed out.
cannot have been manufactured locally, as the remains of spoilt
1 At Southend, Trinity H.W. mark is 121/2 ft. above Ordnance Datum. For Thorny Crock
a figure of 13 ft. is taken; this figure is confirmed by the level of sea-weed on the wall.