Kimmeridge clay facts for kids

Quick facts for kids Kimmeridge Clay Stratigraphic range: Kimmeridgian-Tithonian
Grey cliffs of Upper Kimmeridge Clay above the beach at Egmont Bight
Type	Geological formation
Unit of	Ancholme Group
Lithology
Primary	Mudstone
Other	Siltstone, Sandstone, Conglomerate
Location
Region	England (surface) North Sea (subsurface)
Country	England
Type section
Named for	Kimmeridge Bay

The Kimmeridge Clay is a special type of rock. It's made from mud and clay that settled at the bottom of the ocean a very long time ago. You can find many fossils in it!

This rock formed during the Upper Jurassic period, which was about 157 to 152 million years ago. It's found mostly in Europe. The Kimmeridge Clay is so important that a part of the Late Jurassic period is actually named after it: the Kimmeridgian stage.

This clay is super important because it's the main source of oil found in the North Sea.

What is Kimmeridge Clay?

The Kimmeridge Clay is a sedimentary rock formation. This means it was formed from layers of mud and clay that built up over millions of years. These layers settled at the bottom of a warm, shallow sea. Over time, the layers were pressed together and turned into rock.

Where is it Found?

The Kimmeridge Clay gets its name from a small village called Kimmeridge in Dorset, England. You can see these rocks clearly along the coast there. This area is part of the famous Jurassic Coast World Heritage Site.

The Kimmeridge Clay stretches across England. It forms a band from Dorset in the southwest, all the way northeast to East Anglia and Hull. Even the huge River Humber Bridge has its foundations in the Kimmeridge Clay deposits!

Amazing Fossils Found in Kimmeridge Clay

Many incredible fossils have been found in the Kimmeridge Clay. These fossils tell us a lot about the ancient life that lived in the Jurassic seas.

You can find fossils of many different sea reptiles, including:

• Turtles
• Crocodiles
• Plesiosaurs (long-necked marine reptiles)
• Pliosaurs (short-necked, powerful marine reptiles)
• Ichthyosaurs (dolphin-like marine reptiles)

Sometimes, even dinosaur fossils are found, though they are rare. This is because dinosaurs lived on land, but their bodies could sometimes wash out to sea.

Besides reptiles, there are also many invertebrate fossils. These are animals without backbones. A common invertebrate fossil found here is Gryphaea, which is a type of ancient oyster.

Why is Kimmeridge Clay Important?

The Kimmeridge Clay is very important for the economy. It's the main source rock for many oil fields in the North Sea. This means that the oil we use today was formed from the ancient organic matter (like tiny plants and animals) trapped within the Kimmeridge Clay. Over millions of years, heat and pressure turned this organic matter into oil.

Some companies, like Cuadrilla Resources, have even explored projects to get oil from the Kimmeridge Clay in the UK.

Images for kids

• 

  Complete specimen of Thrissops

• 

  Caturus furcatus

• 

  Dakosaurus

• 

  Plesiosuchus

• 

  Torvoneustes

• 

  Dacentrurus

• 

  Juratyrant

• 

  Cuspicephalus

• 

  Rhamphorhynchus

• 

  Kimmerosaurus

• 

  Pliosaurus brachydeirus

• 

  Grendelius

• 

  Nannopterygius

• 

  Thalassodraco

• 

  Ophthalmosaurus

• 

  An aptychus with the name Trigonellites latus, from the Kimmeridge Clay Formation

See also

In Spanish: Arcilla de Kimmeridge para niños