VIII.
thin band of clay, which rapidly thickens near the
Martello Tower, and plunges downwards, cutting out
the lower half of the gravel and the London Clay of
the cliff, and passing down to the beach. This is a
freshwater clay, and contains at its base, below the
beach, bones of elephant, rhinoceros, hippopotamus,
&c, with great quantities of shells of land and fresh-
water species, and hazel nuts, twigs, pieces of wood,
&c. Above the beach-line the weather penetrates the
laminae of the clay, and destroys the shells, amongst
which now appear some of brackish-water character,
but mixed still with fresh-water species, whilst at the
top of the cliff, 20 feet above the beach, is Bed Sand
with none but sea shells. The series indicates gradual
submergence, and subsequent elevation to the present
level, though the base of the fresh-water series is still
below the high-water mark.
At Lexden, near Colchester, is a deposit of possibly
somewhat later date than the Clacton beds, for it lies
nearly in the bottom of the Colne Valley, and was
evidently formed by that river. Its chief interest lies
in the occurrence, with bones of elk, elephant, hippo-
potamus, and rhinoceros, of remains of beetles of
Southern type, and in the presence, apparently, of
Man, for a stone which had apparently been burnt
in a fire was found in one of the bed of brickearth.
Much more modern in all probability, but scarcely
less interesting, is the
Submerged Forest, Clacton.
The Rev. O. Fisher thus wrote in 1861:— "For
about 600 yards west of the end of the low cliff [i. e.
about 220 yards west of Martello Tower, No. 5] the
shore at low water is occupied by London clay, and
then commences a submarine forest, with stools of
trees, &c."*
In 1875, when we examined it, the shore was much
covered with sand ; bare London clay appeared near
Martello Tower No. 4, and westward for about 600
yards, when the "forest" appeared for the first time,
and extended about 530 yards further westward.
This bed consists of an unctuous blue clay, full of
twigs and other vegetable remains, about 18 inches
thick at the most, and lying on an uneven surface of
London Clay. It is undergoing denudation on the
seaward edge and over the surface, but many stools
and prostrate trunks of trees still exist. These appear
to be of elm, and their roots do not penetrate into the
London Clay. Remains of beetles are found in the
hollow centres of the stools. The general surface is
about 12 feet below high-water mark, and 2 feet above
the low-water mark of spring tides. A report is cur-
rent in the neighbourhood that a parish of the name
* Geol. Mag., vol. v., p. 214.