Prehistoric Dengie Hundred

When mammoths roamed the District

For many millions of years the Dengie 100 was under the sea.

During the Eocene epoch about 55 million years ago Essex was in a shallow tropical sea similar to modern day Malaysia. During this period, over about 3 million years, rivers flowing from the mainland dropped silt which formed the modern London Clay bet that is a predominant feature of our soil.

Into this new clay soil at the bottom of the sea dropped a variety of sea life that became fossilised.

The clay is rich in minerals with selenite , a variety of gypsum, that forms clear crystals.

In more recent times the Thames/Medway River crossed the Dengie Hundred to meet the Sea north of Bradwell on Sea. During this period the river cut into the London clay leaving deposits of sand and gravel . During the Ice Age the Thames became blocked in Hertfordshire by a glacier and a large lake was formed. This lake eventually forced a new path which led to the Thames and Medway adopting its current route.

The ice age brought many new animals with fossils of mammoths, hyena, hippopotamus, wolves and Reindeers all being found in the area. In 1983 a superb Mammoth tusk was found on the shore of the River Crouch at Burnham on crouch by local historian Les Holden. The tusk can be viewed in Chelmsford Museum.

Three sites are especially notes for fossils and geologists alike - Creeksea Cliffs, Maylandsea and Asheldham pits.

Creeksea Cliffs, Althorne

A cliff on the outer bend of the River crouch that is being eroded with fossils that can be found on the shingle beach below the cliffs.

Sharks teeth and other fossils from this site can be viewed in nearby Burnham on Crouch Museum.


At low tide Sharks teeth ,stems of the sea lily and fossilised lobsters can be found in the River Blackwater from Maylandsea to Steeple.

Asheldham Pits

A line of flooded gravel pits stretches across the Dengie Peninsula from Bradwell on Sea to Burnham on Crouch. They are sited on the route of the Thames/Medway River.