The Essex Naturalist 149
Geological sites
About 25 of the Essex SSSIs are notified wholly or in part for their geological or
geomorphological features. Frequently, these are very small sites: as the notified
interest is geological they may be less sensitive to off-site damage. In some cases,
the geological interest is accessible, as part of a quarry for example; in others, it
may be hidden, and thus accessible only by excavation or through bore-holes, as
with the Little Oakley Channel Deposit which on the surface is just an arable
field.
Most of the geological sites ate Pleistocene deposits, gravels which tell the
complex story of the diversion of the Thames into its current position through
the last glacial period. Interpretation of these gravel deposits is a specialist task,
and the purpose of these SSSIs is largely to maintain a reference series of sites to
assist future geological investigations and education.
Other geological interest features are restricted to particular sites: Marks Tey
Brickpit contains a uniquely complete fossil record through the Hoxnian
interglacial, Harwich Foreshore displays an Eocene fossil flora and The Cliff,
Burnham-on-Crouch is important for fossil birds and fish, also from the Eocene
London Clay.
The most dramatic site in Essex is The Naze, where the eroding cliffs reveal
both London Clay, rich in bird, fish and plant fossils, and Red Crag, the earliest
accessible, dateable evidence of the onset of the last Ice Age in north-west
Europe.
Geomorphological sites, such as parts of the Colne Estuary and Dengie, are
noted for their classic salt marsh, shingle and shell bank structures. Also in this
category is the River Ter, a small section of which is notified for the features it
displays of riverine morphology in response to a variable flow regime.
The future
As stated previously, we now consider that the SSSI series in Essex is almost
complete. An ongoing need is for continued vigilance in protecting the
resource, against both development and unsympathetic management. English
Nature has embarked on a programme of agreeing and implementing positive
management with key owners of all sites, to ensure that the special interest
features are at least maintained, if not enhanced. Other mechanisms are
essential in achieving this; for example, many of the coastal sites are receiving
better management under the Environmentally Sensitive Areas scheme,
operated by the Farming and Rural Conservation Agency, and woodlands are
benefiting from the Forestry Authority's Woodland Grants Scheme.
At the same time, where appropriate, other conservation designations are
being made, to enhance the level of protection of the sites. Several sites, on the
coast and Hatfield Forest and Hales Wood, have been declared National Nature
Reserves by English Nature, and others as statutory Local Nature Reserves by