15
THE IMPORTANCE OF THE EAST THAMES CORRIDOR
The flora and fauna of the whole Thames Valley east of London (the East Thames
Corridor, now renamed the Thames Gateway to encourage major development in the
area) appears to contain continental and mediterranean elements unique to this part of
Britain. The area has the lowest rainfall and is one of the wannest parts of country,
warmer for example than Kent, further south. The average winter temperatures are
however several degrees colder than those of south-western England, resulting in a
greater range of temperature and a more continental climate than the rest of Britain.
The Essex side of the Thames may be the most important, certainly for thermophilous
species, because of the presence of south facing escarpments. Between Purfleet and
Grays the Upper Chalk and Thanet Sand outcrops. Just east of Grays there are further
south and west facing escarpments of Thames Terrace gravels at Chadwell and West
Tilbury. South-facing escarpments continue to stretch towards Southend-on-Sea where
there are the London Clay and gravel escarpments of the Benfleet and Hadleigh Downs.
The Purfleet - Grays area has a long history of chalk extraction. In the past chalk was
quarried for use in strengthening river-walls, building and soil improvement. Old leases
dated 1574 and 1594 are known for chalk pits at Purfleet. I believe much of our present-
day fauna in this region is likely to be a (now much impoverished) survival from this past.
In more recent times quarrying has been much more extensive, the cement industry for
example using the chalk in large quantities. Quarrying ceased over ten years ago and
there are numerous abandoned chalk and sand exposures of different ages between
Purfleet and Grays. All this land has been viewed as "derelict" land, an eyesore and a
blight on Thurrock. Most has been developed for industrial or retail use and for housing,
and apart from three quarries (Grays Chalk Pit SSSI and the Warren Gorge and Lion
Gorge proposed Local Nature Reserves) what is left is in imminent danger of destruction
for ever. Unfortunately these three quarries do not contain the same important elements of
habitat that are found in the threatened Mill Wood Pit site described in Newsletter No. 11:
here old habitats such as Mill Wood itself and some calcareous grassland are adjacent to
the more recent disturbed habitats produced by chalk quarrying and sand extraction.
Together with south facing slopes this combination has produced a variety of flower-rich
habitats, sparsely vegetated ground, sand faces and warm sheltered habitats that provide
many invertebrates especially hymenoptera with good foraging and nesting sites and also
allowed a history of movement between populations.
It is essential that these already fragmented south Essex sites are thoroughly surveyed
quickly and measures taken them before it is too late to avoid the loss of this special
fauna.
Peter Harvey
CONTRIBUTIONS TO THE NEXT NEWSLETTER
Please send contributions for the next Newsletter, due out at in
April, to the Editor, Mr Peter Harvey, 9 Kent Road, Grays,
RM17 6DE first week of April.