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these are particularly rare. A friend,
however, was sitting on the slipped material
during a brief visit not so long ago when he
picked up a superb three inch tooth of the
shark Car charadon megalodon. This giant
shark is estimated to have been between 50 and
60 feet in length with a mouth gape of some 6
feet, and was the largest shark ever to have
existed.
A sieve is a useful item of equipment for
locating some of the smaller Crag fossils
particularly the tiny sharks teeth which are
quite common. Sharks teeth can also be found
on the beach but many of these are washed
directly out of the London Clay. The remains
of turtles and crabs and fragments of palm
trees have also been recorded from the London
Clay together with small molluscs and much
fossil wood. Most of these fossils are
pyritized and are therefore somewhat unstable
unless suitably treated. A considerable
amount of pyrite is present on the beach and i
used to be collected in the past for making
sulphuric acid. Bird bones have also been
found amongst the beach shingle, again derived
from the London Clay.
On top of the cliffs there are other sediments
which are of interest. The Red Crag passes
upwards into a number of bedded sand, silt, an
clay layers and overlying this is a layer of
coarser sand and gravel. These gravels are
believed to have been deposited by rivers
draining from an ice sheet a short distance to
the north. The contorted nature of these
deposits shows that the climate was very cold.