4287 x 2848 px | 36,3 x 24,1 cm | 14,3 x 9,5 inches | 300dpi
Data acquisizione:
21 giugno 2010
Ubicazione:
Old Harry Rocks, Studland, Isle of Purbeck, Dorset, England, United Kingdom, UK, Great Britain, GB.
Altre informazioni:
The striking white chalk of Old Harry Rocks, in Dorset, was formed towards the very end of the Cretaceous period, over 65 million years ago.Chalk is almost pure limestone made from trillions of microscopic plankton skeletons as well as bone and shells from larger creatures which once lived in the warm calm waters of a prehistoric sea. Far across the water to the east is a similar row of massive chalk stacks, the Needles, on the Isle of Wight. They are part of the same band of chalk which only a few thousand years ago was connected to the mainland and would have been a continuation of the same formation as Old Harry Rocks and Ballard Down on the Isle of Purbeck. To form the stacks, the sea gradually eroded along the joints and bedding planes, where the softer chalk meets harder bedrock, creating caves. These caves eventually eroded right through creating arches. Subsequently the ceilings of these arches collapsed leaving the upright stacks standing. Over time the stacks themselves will be undermined by the waves and they too will finally tumble into the sea. The process is continuous, Old Harry lost his previous wife in 1896, when she fell and was washed away, but now he has a new one.
