Wikipedia

Jurassic Coast

TheJurassic Coast(alsoDorset and East Devon Coast) is aWorld Heritage Siteon theEnglish Channelcoast of southern England. It stretches fromExmouthinEast DevontoStudland BayinDorset,a distance of about 96 miles (154 km), and was inscribed on the World Heritage List in mid-December 2001.[1]

Dorset and East Devon Coast
UNESCO World Heritage Site
Gad Cliff to St Alban's Head
LocationUnited Kingdom
CriteriaNatural: viii
Reference1029
Inscription2001 (25thSession)
WebsiteOfficial website
Coordinates50°42′20″N2°59′24″W/ 50.70556°N 2.99000°W/50.70556; -2.99000
Jurassic Coast is located in England
Jurassic Coast
Location of Jurassic Coast in England

The site spans 185 million years of geological history,coastal erosionhaving exposed an almost continuous sequence of rock formation covering theTriassic,JurassicandCretaceousperiods. At different times, this area has been desert, shallow tropical sea and marsh, and thefossilisedremains of the various creatures that lived there have been preserved in the rocks.

Natural features seen on this stretch of coast includearches,pinnacles and stack rocks. In some places the sea has broken through resistant rocks to producecoveswith restricted entrances and, in one place, theIsle of Portlandis connected to the land by abarrier beach.In some parts of the coast,landslidesare common. These have exposed a wide range of fossils, the different rock types each having its own typical fauna and flora, thus providing evidence of how animals and plants evolved in this region.

The area aroundLulworth Covecontains afossil forest,and 71 different rock strata have been identified atLyme Regis,each with its own species ofammonite.The fossil collectorMary Anninglived here and her major discoveries of marine reptiles and other fossils were made at a time when the study ofpalaeontologywas just starting to develop. TheCharmouth Heritage Coast Centreprovides information on the heritage coast, and the whole length of the site can be visited via theSouth West Coast Path.

World Heritage Site

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The Jurassic Coast stretches fromOrcombe PointnearExmouthinEast DevontoOld Harry RocksnearSwanagein EastDorset,a distance of 96 miles (154 km). Inscribed on the World Heritage List in 2001, the Jurassic Coast was the first wholly natural World Heritage Site to be designated in the United Kingdom.[2]At Orcombe Point, the "Geoneedle" (2002), an acute pyramidal sculpture, marks the western end of the heritage site; this is built out of fragments of the different types of rocks to be seen along the coast.[3]

The UNESCO World Heritage Committee nomination document lists eight segments of coast included in the site.[4]The segments are:

The cliffs on this part of the coast are being eroded as sections crumble away and landslides occur. These processes reveal successive layers of sedimentary rock, uncovering the geological history at the modern coastline over a period of 185 million years, and disclosing an almost continuous sequence of rock formations covering theTriassic,JurassicandCretaceousperiods.[5]The fossils found in the area and the coastal geomorphologic features of this dynamic coast, have advanced the study of earth sciences for more than two hundred years. The area covered by the designation comprises the land between the mean low water mark and the top of the cliffs or the back of the beach.[5]

The fossils found in abundance along this coastline provide evidence of how animals and plants evolved in this region. During the Triassic this area was a desert, while in the Jurassic it was part of a tropical sea, and in the Cretaceous it was covered by swamps. The fossilised remains of the animals and plants that lived in those periods are very well preserved, providing a wealth of information on their body shapes, the way they died and even the fossilised remains of their last meals. Fossil groups found here includecrustaceans,insects,molluscs,echinoderms,fish,amphibians,reptilesand a fewmammals.AtLulworth Covethere is a fossil forest ofconifers,tree-fernsandcycads.[6]

Geography

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Lyme Bay
Coastal rock on the Jurassic Coast
Durdle Door
The Jurassic limestones on the Isle of Portland have been extensively quarried.

The Jurassic Coast consists ofTriassic,JurassicandCretaceouscliffs, spanning theMesozoic,documenting 185 million years ofgeologicalhistory. The site can be best viewed from the sea, when the dipping nature of the rock strata becomes apparent.[7]

In East Devon, the coastal cliffs consist of steep cliffs of red sandstone from the Triassic, and atBudleigh Salterton,the gravel cliffs contain redquartzitepebbles which accumulate on the beach below as Budleigh pebbles, locally protected.[8]Further east atLadram Bay,more sandstone cliffs give rise to spectacular red sandstone stacks.

AroundLyme RegisandCharmouththe cliffs are of Jurassic clays and shale, and landslips are common.Chesil Beachis a good example of abarrier beachand stretches for 18 miles (29 km) fromBurton Bradstockto theIsle of Portland.The beach encloses an intertidal lagoon which is an internationally importantRamsar Conventionsite known for itsbiodiversity.

AtLulworth Cove,the waves have cut their way through the resistantPortland stoneand created a horseshoe-shaped cove by eroding the softer sands and clays behind. Another feature of this part of the coast isDurdle Door,a natural arch.Sea stacksand pinnacles, such asOld Harry Rocksat Handfast Point, have been formed by erosion of the chalk cliffs.[9]

The highest point on the Jurassic Coast, and on the entire south coast of Britain, isGolden Capat 627 ft (191 m) between Bridport and Charmouth.[10]

This coast shows excellent examples of landforms, including thenatural archat Durdle Door, thecoveandlimestone foldingat Lulworth Cove and atied island,the Isle of Portland. Chesil Beach is a fine example of both atombolo(a deposition landform in which an island is attached to the mainland by a narrow piece of land such as a spit or bar) and astorm beach(a beach affected by particularly fierce waves). The site has stretches of bothconcordantanddiscordantcoastlines. Due to the quality of the varied geology, the site is the subject of internationalfield studies.[11]

The many sedimentary layers on this coastline are rich with fossils, the remains of the animals and plants present in the area whose tissues became immersed in deposits of mud which later hardened into rock. AtLyme Regis,for example, geologists have identified 71 layers of rock, each one containing fossils of a different species of ammonite.[12]

History

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At the end of the 18th centuryGeorges Cuviershowed that some fossil animals resembled no living ones, thus demonstrating that animals could becomeextinct;this led to the emergence ofpalaeontology,the study of fossils.[13]The coasts of eastern Devon and western Dorset were rich in fossil beds, but before this time the fossils had merely been gathered as a pastime or collected by local residents and sold to visitors as curios.

Mary Anning(1799–1847) lived inLyme Regisand followed in her father's footsteps as a collector. She became an expert on the fossils to be found in theBlue Liasaround the town and discovered the first completeIchthyosaurskeleton atThe Spittles.Other important discoveries of ichthyosaurs,plesiosaursand apterosaurfollowed, as well as invertebrates such ascephalopodsand their ink sacs.[14]

DuringWorld War IIseveral sections of the Jurassic Coast became the property of theMinistry of War.One of theRoyal Navy's largest bases was atPortland Harbour,though it has since closed. A major army base atBovingtonremains in use today. Large areas of land, including the coast betweenLulworth CoveandKimmeridge,are still only partially accessible; this includes the ghost village ofTynehamwhich was evacuated after being requisitioned by the army in 1943.[15]

Areas of the coast near Exmouth,The Fleet LagoonatWeymouthand the beaches atStudlandhave also been used for military training but have since been returned to civilian use.

Parts of the coast, especially around Portland, can be dangerous, and shipwrecks have been a feature of the coast. In January 2007 the coast experienced its most environmentally damaging wreck when theMSCNapoli,a 2,400 capacity container ship, was beached atBranscombenearSidmouth,losing oil and cargo.[16]

Management and access

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The Jurassic Coast west ofSt Aldhelm's Head

The Jurassic Coast is subject to severe weather conditions at times. Violent storms occurred in 1824 and 1974, and these and various lesser storms have battered the cliffs and caused flooding and structural damage in coastal towns. The coast is largely an eroding landscape and management of the site aims to allow the natural processes of erosion to continue while protecting people and property.[17]Coastal defences have been put in place in Charmouth and Weymouth, where houses are at risk, but in other places, where the coastline remains in a natural state, the management policy is to take no action and allow erosion to take its course.[9]

TheCharmouth Heritage Coast Centreis an independent educational charity situated near the beach in Charmouth; it provides information and displays on the geology of the area and the wildlife, including a large collection of fossils and a rockpool aquarium. Family fossil-hunting trips are organised from here as well as other events and activities related to the geology and natural history of the area.[18]

The entire length of the coast can be walked on theSouth West Coast Path.[19]Landslipsand rockfalls are a continuing feature of the evolution of this coast. On 6 May 2008, a 1,300 ft (400 m) section of the coast was dramatically re-shaped after a landslip that was described as the worst in 100 years.[20]There was a fatality in 2012 when 400 tonnes (390 long tons) of rock fell onto the beach atBurton Bradstock[21]and another cliff fall took place in 2016 atWest Bay,nearBridport.[22]There was a further cliff collapse at Hive Beach near the village ofBurton Bradstockshortly before dawn on 29 August 2020 after prolonged rain fall. The public were warned to stay clear of the unstable rocks.[23]On 15 April 2021, a further collapse occurred. The collapse was described as being the biggest UK rockfall in 60 years.[24]

See also

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References

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  1. ^"World Heritage Committee Inscribes 31 New Sites on the World Heritage List".UNESCO. 14 December 2001.Archivedfrom the original on 12 June 2016.Retrieved9 September2016.
  2. ^"Dorset and East Devon Coast".UNESCO World Heritage Centre. 2001.Archivedfrom the original on 22 February 2007.Retrieved14 January2007.
  3. ^Harris, Paul (2014).The Jurassic Coast: Britain's Heritage Coast.Amberley Publishing Limited. p. 1.ISBN978-1-4456-1922-4.
  4. ^Nomination of the Dorset and East Devon Coast for Inclusion in the World Heritage List (Report). Dorset County Council. 2000. p. 8.
  5. ^ab"What is the Jurassic Coast?".Jurassic Coast World Heritage Site. 2016.Archivedfrom the original on 22 July 2016.Retrieved17 August2016.
  6. ^"Fossils of the Jurassic Coast".Jurassic Coast World Heritage Site. 2016.Archivedfrom the original on 27 August 2016.Retrieved17 August2016.
  7. ^"Highlight: The Coast from the Sea".Jurassic Coast World Heritage Site. 2016.Archivedfrom the original on 27 August 2016.Retrieved17 August2016.
  8. ^"Budleigh Pebbles".Jurassic Coast Trust.Archivedfrom the original on 23 November 2021.Retrieved23 November2021.
  9. ^abFord, Anjana K. (1 June 2011)."Dr Anjana K. Ford answers questions on the Jurassic Coast".Royal Geographical Society. Archived fromthe originalon 26 August 2016.Retrieved17 August2016.
  10. ^Turnbull, Ronald (2015).Walking the Jurassic Coast: Dorset and East Devon.Cicerone Press. p. 115.ISBN978-1-78362-218-4.
  11. ^Edwards, Richard Anthony (2008).Geology of the Jurassic Coast: The Red Coast Revealed: Exmouth to Lyme Regis.Coastal Pub.ISBN978-0-9544845-4-5.
  12. ^Turnbull, Ronald (2015).Walking the Jurassic Coast: Dorset and East Devon.Cicerone Press. p. 31.ISBN978-1-78362-218-4.
  13. ^McGowan, Christopher (2001).The Dragon Seekers.Persus Publishing. pp.3–4.ISBN0-7382-0282-7.
  14. ^Cadbury, Deborah (2000).The Dinosaur Hunters: A True Story of Scientific Rivalry and the Discovery of the Prehistoric World.Fourth Estate. pp. 4–5.ISBN978-1-85702-963-5.
  15. ^Harris, Paul (2014).The Jurassic Coast: Britain's Heritage Coast.Amberley Publishing Limited. p. 86.ISBN978-1-4456-1922-4.
  16. ^BBC News,2007.Stricken cargo ship run agroundArchived27 February 2007 at theWayback Machine.
  17. ^Sue Paz (6 October 2012)."Jurassic Coast: Safeguarding Dorset's eroding coastline".BBC.Archivedfrom the original on 12 December 2013.Retrieved15 April2014.
  18. ^"Charmouth – Gateway to the Jurassic Coast".Charmouth Portal.Archivedfrom the original on 12 August 2016.Retrieved18 August2016.
  19. ^"The Official Guide to the SWCP".South West Coast Path.SWCP Team. 2004.Archivedfrom the original on 8 September 2015.Retrieved17 August2016.
  20. ^BBC News,2008.Landslip is 'worst in 100 years'Archived10 May 2008 at theWayback Machine.
  21. ^"Cliff landslip death: Charlotte Blackman '10ft from safety'".BBC News.18 December 2012.Retrieved7 February2024.
  22. ^"Large rockfall at West Bay on Jurassic Coast".The Guardian.17 August 2016.Archivedfrom the original on 17 August 2016.Retrieved17 August2016.
  23. ^"Jurassic Coast cliff fall: Warnings after cliff collapse at Hive Beach".BBC News.29 August 2020.Archivedfrom the original on 29 August 2020.Retrieved29 August2020.
  24. ^"Jurassic Coast cliff collapses in biggest UK rockfall for 60 years".The Guardian.15 April 2021.Archivedfrom the original on 17 April 2021.Retrieved17 April2021.

Further reading

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  • Brunsden, Denys, ed. (2003).A Walk Through Time: The Official Guide to the Jurassic Coast.Coastal Publishing.ISBN978-0-9544845-0-7.
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