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Jurassic (ca.200Ma – 145Ma)

The mass extinction of the Permo-Triassic ca. 250Ma ago brought to an end the tenure of many so-called Palaeozoic life forms such as trilobites and eurypterids (sea-scorpions). This is amply reflected by the lack of fossils in beds of this age which occur between Seaton Carew and Redcar.

The loss of diversity left a much reduced biota but the survivors gradually diversified and radiated into the wealth of vacant niches left by the mass extinction. The changes in body-plan that occurred led to onset of the Mesozoic Era of life.

At Redcar the barren rocks of the Triassic give way to fossil-rich limestone and shale of the Lower Jurassic, a change which took place ca.200Ma ago. The Jurassic Period is probably the most widely-known geological division amongst non-geologists thanks to films like Jurassic Park.

Rocks south of the River Tees underlying East Cleveland, and the North York Moors, are almost entirely Jurassic in age and can be subdivided into Lower and Middle episodes depending upon environment of deposition. The transition between the two is marked by a change between marine conditions of the Lower Jurassic to an advancing river delta of the Middle Jurassic.

There are two further Jurassic areas of our site to explore:

lower jurassic middle hurassic
Lower Jurassic                                         Middle Jurassic

If you have a question about your local geology, or a rock, mineral or fossil you’d like identified then please visit our Contact Us page and we will do our best to help.


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Redcar Submerged Forest View north from Skelton View north-east from Loftus Quarries

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As a body of volunteers Tees Valley RIGS Group receives no direct funding but can bid for small amounts from funding bodies such as HLF (Heritage Lottery Fund), ALSF (Aggregates Levy Sustainability Fund), and so on when such monies are ...