Looking out
across Swindon's Front Garden you get the chance of seeing both older
and younger rock formations together.
Old
Clay
The valley
below, with the M4 cutting across it, is made up of Kimmeridge Clay which
was laid down in a deep open muddy sea
97 million years ago during the Cretaceous Period.
Compared to the choppy seas that created Swindon's Portland Beds, Kimmeridge
Clay seas were quieter, darker and less oxygenated.
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How Swindon's Front Garden may have
looked during the Jurassic Period |
As a result
it's here in the Kimmeridge Clay that most of Swindon's large fossils
have been found.
The valley was used by early man as a source of fuel and clay for pottery
and between 500-2000 BC local Swindonians would have let their pigs forage
in the woodlands that covered the clay valleys.
But for later
generations the clay soil proved to be less profitable. Too heavy and
sticky for crops it could only be used for pastureland. You can still
see traces today where the clay lands were farmed. Between West Leaze
and West Leaze Farm you can still see the ghost of a former village street,
boundaries and earthworks.
Young
Chalk
To your left
you can see the large tracts of chalk of the Marlborough Downs.
Chalk is
one of the youngest rock formations in the Swindon area and was formed
in the Cretaceous period just 74 million years ago.
At the start
of the Cretaceous Period, after the plug was pulled on the Jurassic Sea,
the sea started to come back again.
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A Megalosaurid dinosaur's foot found
in Swindon's Kimmeridge Clay |
It started
off as a series of swampy lagoons that gradually became a proper marine
sea and finally a pure tropical sea with no sand or mud.
Millions
and millions of tiny alga blooms lived in the chalk seas of Swindon. They
produced a calcium carbonate skeleton which, when they died, hardened
and rained down on the seabed below.
Layer upon
layer of these micro skeletons piled up until they were eventually compacted
and hardened to form chalk.
Ideal as
arable land the Chalk slopes proved far more profitable than the low lying
clay valleys and large prosperous communities like Chiselden started springing
up that are still around today.
Looking across
to the left you can also see the Ridgeway which is possibly the oldest
road in Europe. Stone Age man walked along its route long before the likes
of Stonehenge came into being and even before Britain was an Island. It
is the oldest surviving relic from our human past.
...walk for quarter of a mile until you reach a footpath that runs
under the Old Town Rail Path. Take the steps, on the right, down to the
path and turn right. Walk up the hill towards Westlecot Road. Walk along
Westlecot Road for a quarter of a mile until you reach Town Gardens. Turn
left into The Quarries just before the entrance to Town Gardens.
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