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Pre - History
Long
before man had penetrated the wilds of East Anglia, the geological
formation of the area had taken place. The arrival of the Ice Age
brought glaciers covering large areas of the county of Suffolk as we now know it. Glaciers which advanced and
retreated several times over
a period of a million years created the form of land surface we have.
They broke up the underlying materials, and with the alternate
freezing and warming process, left us with mixed sands, loams and
clays distributed all over the area.
About
400,000 BC the Anglian Ice Advance appeared and it covered most of
East Anglia with a layer of ice over 100 metres thick in places,
filling the river valleys. As it melted and ran away, new rivers and
valleys, such as the Blyth and Waveney were formed, and with the
rising of the sea levels, East Anglia took on its familiar rounded
shape. The residue or deposit of boulder clay which had been carried
along by the melting ice was left, covering parts of Halesworth as it
went. Within the clay were fragments of rock and fossils of the
Cretaceous and the Jurassic periods.
The
millions of years of evolution left this residue of fossil remains,
which are readily recognisable when they are turned up by the plough,
rise to the surface of fields, or appear in eroded cliffs. The most
common fossils which have been found in the Halesworth district
include the sea urchin echinoidea. or 'fairy
loaf' as it was called
in Suffolk. It was often polished and placed on the mantelpiece as a
charm to aid the weekly batch of bread being baked. The fossilised
sponge, the gryphaea incurva, known as the 'devil's toenails', being
in fact a fossilised oyster-shell. Then there is the belemnite
fossil, which is a pointed flint cylinder from two to six inches in
length, also called the 'devil's
fingers', which was the fossilised
guard of an extinct cuttle-fish, which was often carried in the
pocket for good luck. A larger fossil, which can look like a coiled
snake is the ammonite cephalopod also known as 'snake-stones', while
occasionally the delicate tracery of shells or of insects comes to
light when flint nodules are split.
Halesworth
itself lies between the 10 metre and 20 metre contours, the lower
slopes of a ridge, and to the east of the town is the Blyth Valley
with its coastal strip of sand and gravel. The Norwich Road (to the
north) inclines
upwards to a plateau of clay at the 40 metre contour, while to the
south and west is clay, peat and silt.
At
the Holton quarry evidence has been found of round pebbles, which
with the brightly coloured sands, called 'kesgrave sands', were
possibly left behind by an early river which flowed into a large
delta at Lowestoft. The Thames and the Rhine were probably
tributaries of a larger river and the Thames had a number of
channels, one of which flowed in this direction. Until something like
8,000 BC, Britain still physically formed part of the continent of
Europe, enabling people to walk in their migratory journeys across
what is now the bed of the North Sea, which was probably fenland,
similar to parts of East Anglia today.
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