The rocks of the East of England represent
some 170 million years of Earth history. The
oldest rocks date back to the Jurassic period,
although much older rocks are present at depth,
and examples of other ancient rocks have been
transported to the region during the Ice Age.
The region's geology may be divided into bedrock (sometimes called the 'solid' geology),
and superficial (sometimes known as 'drift'), which includes sediments laid down over the
last two million years. The structure of the region’s bedrock geology is relatively simple:
the rocks become younger eastwards, and dip gently towards the North Sea basin. By contrast,
the superficial geology is notoriously complex, and continues to excite lively discussion among geologists.
Click on the maps below to view more detail.
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Bedrock geology map
0.5 mb PDF |
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Superficial geology map
0.5 mb PDF |
Click on table below
to
view the
simplified geological
sequence.
Introducing the geology of the East of England
The sediments and fossils of the East of England provide a physical archive
of information about environmental change over deep time. They are particularly
important for telling the story of the last 3.5 million years, including changes
in wildlife and human occupation.
Jurassic
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The oldest rocks in the region are part of the belt of Jurassic limestone
which stretches from Dorset to Yorkshire. They include oolitic limestones
and clays laid down in warm, shallow tropical seas. The limestones have been
used as building stone, as at Barnack near Peterborough.
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Jurassic limestone has been used to build Bromham Bridge, Beds. |
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The Oxford Clay underlies many parts of West Cambridgeshire and Bedfordshire, forming an undulating
plain. It has been an important source of clay for brick making in the Bedford and Peterborough areas.
It is rich in fossil remains, which include ammonites and large marine reptiles such as Plesiosaurus.
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Excavating the Lower Oxford Clay for brick making at Quest Pit, Stewartby, Beds. Pyritic shell beds form orange-brown layers here. |
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The Corallian Beds include a range of marine
clays and limestones containing fossil
ammonites and bivalves. They outcrop in the
St Ives and Ampthill areas, and also in the
form of coral-rich rock at Upware.
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The Corallian Beds exposed at Dimmock's Cote Quarry, at Upware, Cambs. Grey marls can be seen in the foreground, with brown, coral-rich reef limestones topping the sequence. |
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The Kimmeridge Clay is a blue-grey, shaly clay rich in fossils.
It principally outcrops in the eastern part of the Fens as far
north of The Wash, where it forms low-lying land bordering and
underlying the Fens.
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A polished section of an ammonite from the Kimmeridge Clay at Crimplesham Quarry, Norfolk. |
Cretaceous
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The Lower Greensand forms a ridge in Bedfordshire. It has been quarried for sand around Leighton Buzzard,
Woburn and Sandy. The Carstone rock of West Norfolk is of a similar age, and is quarried for building stone.
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The Woburn Sands Formation of the Lower Greensand is exposed at Deepdale Quarry, Beds. These sandstones were deposited in fairly shallow waters, and show sedimentary structures such as cross-bedding and clay drapes. |
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The Chalk is a white or
grey limestone that totals over 400m in
thickness. It forms the prominent scarp of
the Bedfordshire and Hertfordshire
Chilterns, and continues north as rolling
uplands in Essex and Cambridgeshire, with
more subdued relief in West Suffolk and West
Norfolk. It also forms low hills in the
Thurrock area of south Essex. Flints
originate in it, and were used by early
humans for tool making. It has been
extensively quarried over the centuries for
agricultural and building lime. Today, the
Chalk is the region’s most important source
of drinking water.
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Lower Cretaceous sediments outcrop in colourful bands in Hunstanton Cliffs,
Norfolk. A band of Red Chalk is sandwiched between brown Carstone and white Chalk. |
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