The form of the coastline around Durdle Door is controlled by its geology—both by the contrasting hardnesses of the rocks, and by the local patterns of faults and folds. The arch has formed on a concordant coastline where bands of rock run parallel to the shoreline. The rock strata are almost vertical, and the bands of rock are quite narrow. Originally a band of resistant Portland limestone ran along the shore, the same band that appears one mile along the coast forming the narrow entrance to Lulworth Cove. Behind this is a 120-metre (390 ft) band of weaker, easily eroded rocks, and behind this is a stronger and much thicker band of chalk, which forms the Purbeck Hills. These steeply dipping rocks are part of the Lulworth crumple, itself part of the broader Purbeck Monocline, produced by the building of the Alps during the mid-Cenozoic.
The limestone and chalk are in closer proximity at Durdle Door than at Swanage, 10 miles (16 km) to the east, where the distance is over 2 miles (3 km). Around this part of the coast nearly all of the limestone has been removed by sea erosion, whilst the remainder forms the small headland which includes the arch. Erosion at the western end of the limestone band has resulted in the arch formation. UNESCO teams monitor the condition of both the arch and adjacent beach.
The 120-metre (390 ft) isthmus which joins the limestone to the chalk is made of a 50-metre (160 ft) band of Portland limestone, a narrow and compressed band of Cretaceous Wealden clays and sands, and then narrow bands of greensand and sandstone.
In Man O' War Bay, the small bay immediately east of Durdle Door, the band of Portland and Purbeck limestone has not been entirely eroded away, and is visible above the waves as Man O'War Rocks. Similarly, offshore to the west, the eroded limestone outcrop forms a line of small rocky islets called (from east to west) The Bull, The Blind Cow, The Cow, and The Calf.
As the coastline in this area is generally an eroding landscape, the cliffs are subject to occasional rockfalls and landslides; a particularly large slide occurred just to the east of Durdle Door in April 2013, resulting in destruction of part of the South West Coast Path.
There is a dearth of early written records about the arch, though it has kept a name given to it probably over a thousand years ago. In the late eighteenth century there is a description of the "magnificent arch of Durdle-rock Door", and early nineteenth-century maps called it 'Duddledoor' and 'Durdle' or 'Dudde Door'. In 1811 the first Ordnance Survey map of the area named it as 'Dirdale Door'. 'Durdle' is derived from the Old English thirl, meaning to pierce, bore or drill, which in turn derives from thyrel, meaning hole. Similar names in the region include Durlston Bay and Durlston Head further east, where a coastal stack suggests the existence of an earlier arch, and the Thurlestone, an arched rock in the neighbouring county of Devon to the west. The 'Door' part of the name probably maintains its modern meaning, referring to the arched shape of the rock; in the late nineteenth century there is reference to it being called the "Barn-door", and is described as being "sufficiently high for a good-sized sailing boat to pass through it."
In literature and popular culture
The landscape around Durdle Door has been used in scenes in several films, including Wilde (1997) starring Stephen Fry, Nanny McPhee starring Emma Thompson, the 1967 production of Far From The Madding Crowd (the latter also filmed around nearby Scratchy Bottom), and the Bollywood film Housefull 3.
Ron Dawson's children's story Scary Bones meets the Dinosaurs of the Jurassic Coast creates a myth of how Durdle Door came to be, as an 'undiscovered' dinosaur called Durdle Doorus is magically transformed into rock.
Shall the tide thus ebb and flow for ever?
and for evermore
Rave the wave and glance the ripple through the
rocks at Durdle Door?
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- Aislinn Simpson (13 August 2009). "UAE hotel draws condemnation over use of Durdle Door image on website". The Daily Telegraph. London. Retrieved 8 August 2013.
- "The Purbeck Gazette". Archived from the original on 15 September 2012. Retrieved 6 April 2012.
- Nowell, D. A. G. "The geology of Lulworth Cove, Dorset." Geology Today 14 (1998): 71–74.
- "Lulworth Cove & Crumple – a geography pilgrimage". jurassiccoast.org. Retrieved 12 August 2013.
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- "Monitoring the coast". jurassiccoast.org. Retrieved 12 August 2013.
- Ian West. "Durdle Door, West of Lulworth Cove, Dorset. Geology of the Wessex Coast of Southern England". Retrieved 10 August 2013.
- "Dorset coast path collapse: 'Massive' cliff fall near Durdle Door". BBC News. 30 April 2013. Retrieved 12 August 2013.
- "Locations: Durdle Door". the dorsetpage.com. 2000. Retrieved 11 August 2013.
- "Durdle Door". worldheritagecoast.net. Retrieved 8 August 2013.
- Patrick Hanks, ed. (1985). Collins English Dictionary. William Collins Sons & Co. Ltd. ISBN 0 00 433078-1.
- "Far from the Madding Crowd (1967) — Filming locations". Retrieved 25 October 2008.
- "IDWLF on Twitter". Retrieved 20 May 2017.
- "Book Description on Amazon.co.uk". Retrieved 9 August 2013.
- Moule, Arthur Evans (1879). Songs of heaven and home, written in a foreign land. p. 22.
- Arkell, W.J., 1978. The Geology of the Country around Weymouth, Swanage, Corfe and Lulworth, 4th pr.. London: Geological Survey of Great Britain, HMSO.
- Davies, G.M., 1956. A Geological Guide to the Dorset Coast, 2nd ed.. London: Adam & Charles Black.
- Perkins, J.W., 1977. Geology Explained in Dorset. London: David & Charles.
|Wikimedia Commons has media related to Durdle Door.|
- Photos tagged with "Durdledoor" at Flickr
- "Caves, Arches & Stacks" Southwest Coastal Group
- "Durdle Door: Past and future" animation
- Section of Lulworth Crumple, labelled diagram by Ian West (2013)
- Durdle Door Educational Activity Sheet for Kids at EasyScienceforKids.