The Jurassic Coast

The coast going from the Dorset to East Devon is special because the rocks in its cliffs between Exmouth (East Devon) and Studland (Dorset) contain a record of the Earth’s ancient history through 185 million years, displaying not only superb Jurassic, but older Triassic and younger Cretaceous rocks too. The coast is rich with fossils that provide a record through virtually a third of the evolution of life, including the rise of dinosaurs. The erosion displays spectacular features such as landslides, sea stacks, bays, headlands and beaches. The Jurassic Coast is the England’s first natural World Heritage Site designated by UNESCO in 2001.

The East Devon and Dorset about 230 million years ao was a desert through which vast rivers flowed from mountains in the south, allowing life to get a foothold. Ancient reptiles, such as the Rhynchosaurus spenceri, and giant amphibians lived on the river banks in their vegetation (conifers, cycads, horsetail plants).

RED SANDSTONE. The color depends on the iron oxides of the red desert sand, which was mixed with the fragments of rocks and pebbles carried by the floods and was compressed over the millenia into a distinctive red stone. This red sandstone was exentesively used to build churches, chapels, houses, and city walls in Exeter and other towns of Devon.

WHITE LIMESTONE. Chalk is a soft, white, porous, sedimentary carbonate rock, a type of limestone composed of the mineral calcite (CaCO3). It forms under reasonably deep marine conditions from the gradual accumulation of minute calcite shells of sub-microscopic plankton to the sea floor and then consolidated and compressed during diagenesis. Chalk is derived from Cretaceous deposits, Carboniferous Limestone or Jurassic oolitic limestones.

5 Seaton (5).JPG

Seaton, near to Lyme Regis, displays this type of white coast and the cave complex of Beer, the Beer Quarry Caves, has been prized since Roman times, because of its workability for carving and for its gentle yellow colour on exposure to air. Beer stone was used in the construction of 24 cathedrals around the UK, including Exeter Cathedral and Westminster Abbey.

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Insegnante di Scienze Naturali (Biologia, Chimica, Geologia, Astronomia) presso la scuola secondaria superiore
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