Filey's Jurassic Coast
"There is a rich untapped reservoir
of history, Geology and Archaeology which is unique to our area" - said Tony Green of
the Filey Bay Research Group commenting on the discovery of a Plesiosaur in the
cliffs to the South of Filey.
Filey Bay is the home to the Jurassic
Coast , with the Geologically important Filey Brigg to the north of the bay and
to the South, the famed Speeton clay cliffs, and following on from a fault line
that roughly bisects the Bay in an easterly direction, the white chalk stone cliffs
of the Cretaceous period leading to
Flamborough Head. You can trace back in time when the dinosaurs trod the ooze
of the river estuaries here over 140 million years ago.
Jurassic is the second epoch of the Mesozoic era, lasting for 45 million
years during which dinosaurs and ammonites flourished; from French jurassique
from the Jura mountain range in eastern France.
he substantially complete
skeleton of a plesiosaur was found by an amateur collector, Nigel Armstrong in
the Speeton clay. In an excavation organised by Will Watts the Dinosaur
coast Officer and Dr Phil Manning of the Yorkshire Museum. The well preserved
skeleton was removed from the clay in one block weighing about one and a
half tons. The skeleton was identified as being that of an elasmasaur a long
necked plesiosaur of which there are several types. At this time, there is
a gap in our knowledge about these animals between 100 million years ago and 175
million years ago and this find can shed light on this
This skeleton was removed from the lower beds of Speeton clay and is about 140
million years old.
Manning was quoted as saying "To find such an
important specimen with so many bones in place is fantastic, this creature
should go a long way to filling many of the holes in the evolution of this
group" and it is reported that this is the view shared by Mark Evans of
Leicester Museums who is one of the plesiosaur experts to visit the site who
said " We know about these creatures from 200 million years ago from
places like Whitby and from 90 million years ago from the USA, but there is a
gap in their evolution. This is a missing link in the plesiosaur story".
The Speeton Clay beds are a popular
place for fossil hunters, it is recommended that you look on the friends of
Speeton Clay website link below for a fully comprehensive list of fossil types
and detailed information about the clay itself.
fossil hunters - the Speeton clay cliffs are dangerously unstable and it
is unwise to venture close to them - you have been warned!
in Speeton Clay
||Belemnites in Speeton Clay
For more information on Speeton clay
and the fossils go to
Friends of Speeton
Clay Adam Stuart Smith is acknowledged for the picture of
|Filey Brigg looking to the west
Because of its geological
importance, Filey Brigg to the north of the Bay is a site of Special Scientific Interest (SSSI) and is
also designated as a local Nature Reserve. In the Jurassic period of about
150 million years ago the hard rocks were laid down as silt and the Brigg and
Carr Naze were built up by layers of material that were laid down over the
The Brigg consists of the hard rocks
jutting out to sea in the form of a peninsula topped by the "Boulder Clay"
cliffs known as Carr Naze. The Brigg and Carr Naze are easily identifiable
and they form a recognisable feature that readily identifies with the town of
The Filey Brigg Geological Timeline
||Like all stratified rocks, the rocks
on the Brigg are
formed in layers that can be recognised, the top layer is the clay or Glacial
Till that was brought down by the glaciers during the last Ice Age that finished
about 10.000 years ago. contained in this till are erratics or isolated
rocks and stones that are mixed up in the clay and now form part of the beach at
Filey as they have been washed out of the cliffs.
||The next layer down is a rubble
layer which was formed by the freeze and thaw action on the upper level
Hambleton Oolite below it
(from New Latin oolites literally 'egg stone'.)
|| Upper level Hambleton Oolite
upper is a limestone and within it are to be found fossils of bivalves and
||The Birdsall Calcareous Grit is q very hard rock and is the lowest
visible layer to the left hand side of the Brigg
||Next is the Lower level Hambleton
Oolite consist of shell beds that were formed when warm waters seas the area.
||Below this layer are what are termed
as the passage beds which were the product of the area being covered by a river
||Next we have the Lower Calcareous
Grit which was formed when a warm shallow sea covered the area.
The first picture shows the
weathered Glacial till, the second picture below shows the
rubble layer formed by freeze and thaw action above the stratified rock and
below the Till on the south face of Carr Naze. The third picture shows
fossils amongst fossilised worm burrows in stratified rock. The worm
burrows have filled with a harder material and the softer material round them
have weathered away at a greater rate leaving the burrows exposed above the
surface of the rock.
Carr Naze Glacial Till
eroded and etched in snow
|Rubble layer below the till
Fossil bivalves in
© The Filey Bay Research
Group July 2017
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Archaeology Marine Archaeology
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