Purbeck monocline
The Purbeck Monocline ( English Purbeck Monocline ) is a geological fold that extends from the Purbeck Hills on the Purbeck Peninsula on the south coast of England to the Isle of Wight . It originated during the late Oligocene and early Miocene around 30 million years ago as one of the northernmost events of the Alpine folding , one of the most recent phases of global mountain formation. A monocline is a fold shape in which the local rock layers form a curve that is stepped.
The purbeck-monoclinal seen on the surface as an elongate ridge, of from almost perpendicular rocks the chalk is formed. This ridge runs from Flower's Barrow to Old Harry Rocks , then dips into the sea and runs to The Needles , a well-known chalk cliff, and finally forms the central backbone of the Isle of Wight, where it is also known as the 'Purbeck-Isle of Wight Disturbance' is. The Purbeck Hills separate the small and wide peninsula of the Isle of Purbeck from the English mainland. In the Middle Ages the chalk ridge was an effective barrier and the Isle of Purbeck was literally isolated from the mainland.
The basis of the geological structure of the Isle of Purbeck is the fact that all the layers of rock to the north a fall . The erosion- resistant layers of limestone in this inclined layer package form two ribs, between which the softer clay layers of the so-called Wealden Group have been cleared out and form a valley.
Visible features along the monocline include the disharmonious folds at Stair Hole , Lulworth Cove , Arish Mell, and Peveril Point . Another feature are those of thrusts to polygons collapsed harder rocks under the Kimmeridge Bay . In connection with the development of the monocline, there is a major fault at Ballard Down .
Individual evidence
- ↑ John R. Underhill, Susan. Paterson: Genesis of tectonic inversion structures: seismic evidence for the development of key structures along the Purbeck-Isle of Wight Disturbance . In: Geological Society (Ed.): Journal of the Geological Society . 155, No. 6, December 1998, pp. 975-992. doi : 10.1144 / gsjgs.155.6.0975 . Retrieved November 16, 2010.
- ^ Ian West: Geology Of Stair Hole . 2010. Retrieved November 16, 2010.