60-547: Old Harry Rocks are three chalk formations, including a stack and a stump, located at Handfast Point, on the Isle of Purbeck in Dorset , southern England . They mark the most eastern point of the Jurassic Coast , a UNESCO World Heritage Site . Old Harry Rocks lie directly east of Studland , about 2.5 miles (4 km) north east of Swanage , and about 5 miles (8 km) south of
120-500: A campaign for donations to buy 170 acres (0.7 km ) of land atop Dover's cliffs when it was feared that they might be sold to developers; the campaign met its target after only three weeks. The National Trust, which owns the surrounding areas, plans to return the land to a natural state of chalk grassland and preserve existing military structures from the Second World War. In June 2021, a wildflower meadow on White Cliffs of Dover
180-443: A classroom and exhibition area. Staff and volunteers are available to answer questions and provide information about the wildlife in the reserve. The building's design incorporates eco-construction criteria. The nature reserve is named after the edible plant rock samphire , which grows on the cliffs and used to be gathered by hanging ropes over the cliff's edge. Shakespeare mentions rock samphire in his play King Lear and includes
240-570: A few are more recent. A mixture of chalk and mercury can be used as fingerprint powder . However, because of the toxicity of the mercury, the use of such mixtures for fingerprinting was abandoned in 1967. Dover cliffs The White Cliffs of Dover are the region of English coastline facing the Strait of Dover and France. The cliff face, which reaches a height of 350 feet (110 m), owes its striking appearance to its composition of chalk accented by streaks of black flint , deposited during
300-541: A great sea. The sea bottom was covered with white mud formed from fragments of coccoliths , the skeletons of tiny algae that floated in the surface waters and sank to the bottom and, together with the remains of bottom-living creatures, formed muddy sediments. It is thought that the sediments were deposited very slowly, probably half a millimetre a year, equivalent to about 180 coccoliths piled one on top of another. Up to 500 metres (1,600 ft) of sediments were deposited in some areas. The weight of overlying sediments caused
360-489: A host plant. It has yellow, white, or blue snapdragon-like flowers and about 90 per cent of the UK's population is found on the cliffs. Viper's-bugloss , a showy plant in vivid shades of blue and purple with red stamens, also grows along the cliffs. The abundance of wildflowers provides homes for about thirty species of butterfly. The rare Adonis blue can be seen in spring and again in autumn. Males have vibrant blue wings lined with
420-451: A pair at Dover which helped shipping navigate the port. It is likely the area around the surviving lighthouse was inhabited in the early medieval period as archaeologists have found a Saxon cemetery here, and the church of St Mary in Castro was built next to the lighthouse in the 10th or 11th century. It is thought that the name Albion , an ancient or poetic term referring to Great Britain ,
480-400: A reference to this trade with the lines "Half-way down / Hangs one that gathers samphire; dreadful trade!" (Act IV, Scene VI Lines 14–15). This refers to the dangers involved in collecting rock samphire on sea cliffs. Shakespeare Cliff was named after the reference to this "dreadful trade". Fan Bay Deep Shelter is a series of tunnels constructed during World War II. The tunnels were opened to
540-549: A ridge that acted as a natural dam to hold back a large freshwater pro-glacial lake , now submerged under the North Sea . The land masses remained connected until between 450,000 and 180,000 years ago when at least two catastrophic glacial lake outburst floods breached the anticline and destroyed the ridge that connected Britain to Europe. A land connection across the southern North Sea existed intermittently at later times when periods of glaciation resulted in lower sea levels. At
600-531: A sustainable National Trust visitor centre was built in the area. The Gateway building, designed by van Heyningen and Haward Architects , houses a restaurant, an information centre on the work of the National Trust, and details of local archaeology, history and landscape. During the Late Cretaceous , between 100 million and 66 million years ago, Great Britain and much of Europe were submerged under
660-466: A white margin, whereas the females are a rich chocolate brown. This species' sole larval food plant is the horseshoe vetch and it has a symbiotic relationship with red or black ants. The eggs are laid singly on very small foodplants growing in short turf. This provides a warm microclimate, suitable for larval development, which is also favoured by ants. The caterpillar has green and yellow stripes to provide camouflage while it feeds on vetch. The ants milk
SECTION 10
#1732855983671720-534: A year, and that the erosion is caused by the loss of beach underneath the cliffs exacerbated by stronger storms and human activity such as gravel extraction. Despite this, the cliffs are expected to survive for tens of thousands of years more. In 2001, a large chunk of the cliff edge, as large as a football pitch , fell into the Channel. Further large sections collapsed on 15 March 2012, 4 February 2020, and on 3 February 2021. The chalk grassland environment above
780-633: Is mined from chalk deposits both above ground and underground . Chalk mining boomed during the Industrial Revolution , due to the need for chalk products such as quicklime and bricks . Most people first encounter chalk in school where it refers to blackboard chalk , which was originally made of mineral chalk, since it readily crumbles and leaves particles that stick loosely to rough surfaces, allowing it to make writing that can be readily erased. Blackboard chalk manufacturers now may use mineral chalk, other mineral sources of calcium carbonate, or
840-588: Is a 10-mile-long (16 km) sandbank at the southern end of the North Sea lying six miles (10 km) off the Deal coast. The area consists of a layer of fine sand approximately 82 ft (25 m) deep resting on a chalk platform belonging to the same geological feature that incorporates the White Cliffs of Dover. More than 2,000 ships are believed to have been wrecked on the Goodwin Sands because they lie close to
900-610: Is a fine-textured, earthy type of limestone distinguished by its light colour, softness, and high porosity. It is composed mostly of tiny fragments of the calcite shells or skeletons of plankton , such as foraminifera or coccolithophores . These fragments mostly take the form of calcite plates ranging from 0.5 to 4 microns in size, though about 10% to 25% of a typical chalk is composed of fragments that are 10 to 100 microns in size. The larger fragments include intact plankton skeletons and skeletal fragments of larger organisms, such as molluscs , echinoderms , or bryozoans . Chalk
960-404: Is a soft, white, porous , sedimentary carbonate rock . It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor . Chalk is common throughout Western Europe , where deposits underlie parts of France, and steep cliffs are often seen where they meet the sea in places such as
1020-508: Is also the only form of limestone that commonly shows signs of compaction. Flint (a type of chert ) is very common as bands parallel to the bedding or as nodules in seams , or linings to fractures , embedded in chalk. It is probably derived from sponge spicules or other siliceous organisms as water is expelled upwards during compaction. Flint is often deposited around larger fossils such as Echinoidea which may be silicified (i.e. replaced molecule by molecule by flint). Chalk
1080-428: Is applied to the hands and feet to remove perspiration and reduce slipping. Chalk may also be used as a house construction material instead of brick or wattle and daub : quarried chalk was cut into blocks and used as ashlar , or loose chalk was rammed into blocks and laid in mortar. There are still houses standing which have been constructed using chalk as the main building material. Most are pre- Victorian though
1140-706: Is closest to continental Europe , on a clear day the cliffs are visible from France, approximately 20 miles (32 km) away. A celebrated UK landmark, the cliffs have featured on commemorative postage stamps issued by the Royal Mail , including in their British coastline series in 2002 and UK A-Z series in 2012. The cliffs are part of the coastline of Kent in England between approximately 51°06′N 1°14′E / 51.100°N 1.233°E / 51.100; 1.233 and 51°12′N 1°24′E / 51.200°N 1.400°E / 51.200; 1.400 , at
1200-518: Is commonly used as a drying agent to obtain better grip by gymnasts and rock climbers. Glazing putty mainly contains chalk as a filler in linseed oil . Chalk and other forms of limestone may be used for their properties as a base . Chalk is a source of quicklime by thermal decomposition , or slaked lime following quenching of quicklime with water. In agriculture , chalk is used for raising pH in soils with high acidity . Small doses of chalk can also be used as an antacid . Additionally,
1260-520: Is now usually made of talc (magnesium silicate). Chalk beds form important petroleum reservoirs in the North Sea and along the Gulf Coast of North America. In southeast England, deneholes are a notable example of ancient chalk pits. Such bell pits may also mark the sites of ancient flint mines, where the prime object was to remove flint nodules for stone tool manufacture. The surface remains at Cissbury are one such example, but perhaps
SECTION 20
#17328559836711320-586: Is so common in Cretaceous marine beds that the Cretaceous Period was named for these deposits. The name Cretaceous was derived from Latin creta , meaning chalk . Some deposits of chalk were formed after the Cretaceous. The Chalk Group is a European stratigraphic unit deposited during the late Cretaceous Period. It forms the famous White Cliffs of Dover in Kent , England, as well as their counterparts of
1380-401: Is typically almost pure calcite, CaCO 3 , with just 2% to 4% of other minerals. These are usually quartz and clay minerals , though collophane (cryptocrystalline apatite , a phosphate mineral) is also sometimes present, as nodules or as small pellets interpreted as fecal pellets. In some chalk beds, the calcite has been converted to dolomite , CaMg(CO 3 ) 2 , and in a few cases
1440-723: The Cap Blanc Nez on the other side of the Dover Strait . The Champagne region of France is mostly underlain by chalk deposits, which contain artificial caves used for wine storage . Some of the highest chalk cliffs in the world occur at Jasmund National Park in Germany and at Møns Klint in Denmark . Chalk deposits are also found in Cretaceous beds on other continents, such as the Austin Chalk , Selma Group , and Niobrara Formations of
1500-477: The Devil (traditionally known euphemistically as "Old Harry") slept on the rocks. Another local legend says that the rocks were named after Harry Paye , the infamous Poole pirate , whose ship hid behind the rocks awaiting passing merchantmen. Yet another tale has it that a ninth-century Viking raid was thwarted by a storm and that one of the drowned, Earl Harold, was turned into a pillar of chalk. Chalk Chalk
1560-525: The Dover cliffs on the Kent coast of the English Channel . Chalk is mined for use in industry, such as for quicklime , bricks and builder's putty , and in agriculture , for raising pH in soils with high acidity . It is also used for " blackboard chalk " for writing and drawing on various types of surfaces, although these can also be manufactured from other carbonate-based minerals, or gypsum . Chalk
1620-546: The Late Cretaceous . The cliffs, on both sides of the town of Dover in Kent , stretch for eight miles (13 km). The White Cliffs of Dover form part of the North Downs . A section of coastline encompassing the cliffs was purchased by the National Trust in 2016. The cliffs are part of the Dover to Kingsdown Cliffs Site of Special Scientific Interest and Special Area of Conservation . The point where Great Britain
1680-480: The National Trust , Natural England , and County Wildlife Trusts to maintain vegetation on nature reserves. The cliffs are the first landing point for many migratory birds flying inland from across the English Channel. After a 120-year absence, in 2009 it was reported that ravens had returned to the cliffs. Similar in appearance but smaller, the jackdaw is abundant. The rarest of the birds that live along
1740-540: The little ships in the Dunkirk evacuation saw the welcoming sight of the cliffs. In the summer of 1940, reporters gathered at Shakespeare Cliff to watch aerial dogfights between German and British aircraft during the Battle of Britain . Vera Lynn , known as "The Forces' Sweetheart" for her 1942 wartime classic " (There'll Be Bluebirds Over) The White Cliffs of Dover " celebrated her 100th birthday in 2017. That year she led
1800-488: The silver-spotted skipper and straw belle . The well-known red admiral can be seen from February until November. The marbled white , black and white with a white wing border, can be seen from June to August. A possible Iron Age hillfort has been discovered at Dover, on the site of the later castle. The area was also inhabited during the Roman period when Dover was used as a port. A lighthouse survives from this era, one of
1860-411: The English Channel at least twice a year. Among the wildflowers are several varieties of orchids, the rarest of which is the early spider orchid , which has yellow-green to brownish green petals and looks like the body of a large spider. Rock samphire is an edible, salt tolerant succulent plant that grows on the cliff's slopes. The oxtongue broomrape is an unusual plant that lives on the roots of
Old Harry Rocks - Misplaced Pages Continue
1920-639: The Napoleonic Wars, in particular, the defences were remodelled and a series of tunnels were dug into the cliff to act as barracks, adding space for an extra 2,000 soldiers. The tunnels mostly lay abandoned until the Second World War. South Foreland Lighthouse is a Victorian-era lighthouse on the South Foreland in St. Margaret's Bay , which was once used to warn ships approaching the nearby Goodwin Sands . Goodwin Sands
1980-698: The North American interior. Chalk is also found in western Egypt (Khoman Formation) and western Australia ( Miria Formation ). Chalk of Oligocene to Neogene age has been found in drill cores of rock under the Pacific Ocean at Stewart Arch in the Solomon Islands . There are layers of chalk, containing Globorotalia , in the Nicosia Formation of Cyprus , which formed during the Pliocene . Chalk
2040-555: The bottom was so weak the top fell away, leaving a stump. Hydraulic action is the main cause of erosion ( shear force of the waves) that damaged the rock and caused it to fall away. The downlands of Ballard Down are part of the Portsdown Chalk Formation, containing some bands of flint , and were formed 84–72 million years ago in the Campanian age of the Late Cretaceous . The bands of stone have been gradually eroded over
2100-591: The castle to its current size, taking its curtain walls to the edge of the cliffs. During the First Barons' War the castle was held by King John's soldiers and besieged by the French between May 1216 and May 1217. The castle was also besieged in 1265 during the Second Barons' War . In the 16th century, cannons were installed at the castle, but it became less important militarily as Henry VIII had built artillery forts along
2160-464: The centuries, some of the earlier stacks having fallen (Old Harry's original wife fell in 1509), while new ones have been formed by the breaching of narrow isthmuses. Across the water to the east, The Needles on the Isle of Wight are usually visible. These are also part of the same chalk band and only a few thousand years ago were connected to Ballard Down . To form the stacks, the sea gradually eroded along
2220-548: The chalk came mostly form low-magnesium calcite skeletons, so the sediments were already in the form of highly stable low-magnesium calcite when deposited. This is in contrast with most other limestones, which formed from high-magnesium calcite or aragonite that rapidly converted to the more stable low-magnesium calcite after deposition, resulting in the early cementation of such limestones. In chalk, absence of this calcium carbonate conversion process prevented early cementation, which partially accounts for chalk's high porosity. Chalk
2280-405: The cliffs form a symbolic guard. The National Trust calls the cliffs "an icon of Britain", with "the white chalk face a symbol of home and wartime defence." Because crossing at Dover was the primary route to the continent before the advent of air travel, the white line of cliffs also formed the first or last sight of Britain for travellers. During the Second World War, thousands of allied troops on
2340-463: The cliffs is excellent for many species of wild flowers, butterflies and birds, and has been designated a Special Area of Conservation and a Site of Special Scientific Interest. Rangers and volunteers work to clear invasive plants that threaten the native flora. A grazing programme involving Exmoor ponies has been established to help to clear faster-growing invasive plants, allowing smaller, less robust native plants to survive. The ponies are managed by
2400-554: The cliffs is the peregrine falcon . In recent decline, the skylark also makes its home on the cliffs. The cliffs are home to fulmars and to colonies of black-legged kittiwake , a species of gull. Since bluebirds are not indigenous to the UK, some believe that bluebirds, as mentioned in the classic World War II song " (There'll Be Bluebirds Over) The White Cliffs of Dover ", composed by American artists, may actually refer to swallows and/or to house martins , which make an annual migration to continental Europe, many of them crossing
2460-468: The coast. Dover Castle was captured in 1642 during the Civil War when the townspeople climbed the cliffs and surprised the royalist garrison, giving a symbolic victory against royal control. Towards the end of the war many castles were slighted , but Dover was spared. The castle had renewed importance in the 1740s as the development of heavy artillery made capturing ports an important part of warfare. During
Old Harry Rocks - Misplaced Pages Continue
2520-629: The deposits to become consolidated into chalk . British chalk deposits are considered stratigraphically to belong in the Chalk Group . Due to the Alpine orogeny , a major mountain building event during the Cenozoic , the sea-floor deposits were raised above sea level. Until the end of the last glacial period , the British Isles were part of continental Europe, linked by the unbroken Weald-Artois Anticline ,
2580-485: The dolomitized chalk has been dedolomitized back to calcite. Chalk is highly porous, with typical values of porosity ranging from 35 to 47 per cent. While it is similar in appearance to both gypsum and diatomite , chalk is identifiable by its hardness, fossil content, and its reaction to acid (it produces effervescence on contact). In Western Europe, chalk was formed in the Late Cretaceous Epoch and
2640-437: The early Palaeocene Epoch (between 100 and 61 million years ago). It was deposited on extensive continental shelves at depths between 100 and 600 metres (330 and 1,970 ft), during a time of nonseasonal (likely arid) climate that reduced the amount of erosion from nearby exposed rock. The lack of nearby erosion explains the high purity of chalk. The coccolithophores, foraminifera, and other microscopic organisms from which
2700-443: The end of the last glacial period, around 10,000 years ago, rising sea levels finally severed the last land connection. The cliffs' chalk face shows horizontal bands of dark-coloured flint which is composed of the remains of sea sponges and siliceous planktonic micro-organisms that hardened into the microscopic quartz crystals. Quartz silica filled cavities left by dead marine creatures which are found as flint fossils, especially
2760-432: The headland suffered hydraulic action (a process in which air and water are forced into small cracks by the force of the sea, resulting in enlarging cracks), first caves, then arches formed. The tops of the arches collapsed after being weakened by rainfall and wind, leaving disconnected stacks. One of these stacks is known as Old Harry. Old Harry's Wife was another stack which was eroded through corrosion and abrasion, until
2820-411: The internal moulds of Micraster echinoids. Several different ocean floor species such as brachiopods , bivalves , crinoids , and sponges can be found in the chalk deposits, as can sharks' teeth. In some areas, layers of soft, grey chalk known as a hardground complex can be seen. Hardgrounds are thought to reflect disruptions in the steady accumulation of sediment when sedimentation ceased and/or
2880-420: The joints and bedding planes where the softer chalk meets harder bedrock of the rock formations to create a cave. This eventually eroded right through to create an arch. The arch subsequently collapsed to leave the stacks of Old Harry and his wife, No Man's Land (the large outcrop of rock at the end of the cliffs) and the gap of St Lucas' Leap. Old Harry is formed by erosion processes, which will eventually remove
2940-530: The large towns of Poole and Bournemouth . To the south are the chalk cliffs of Ballard Down , much of which is owned by the National Trust . The rocks can be viewed from the Dorset section of the South West Coast Path . The chalk of Old Harry Rocks used to be part of a long stretch of chalk between Purbeck and the Isle of Wight, but remained as a headland after large parts of this seam were eroded away. As
3000-461: The loose surface sediments were stripped away by currents or slumping, exposing the older hardened chalk sediment. A single hardground may have been exhumed 16 or more times before the sediments were compacted and hardened ( lithified ) to form chalk. Thousands of years ago, the cliffs were eroding at 20–60 mm (0.75–2.3 in) a year. Research shows that the erosion rate over the last 150 years has increased to 220–320 mm (8.7–12.6 in)
3060-543: The major shipping lanes through the Straits of Dover . It went out of service in 1988 and is now owned by the National Trust for Places of Historic Interest or Natural Beauty . The cliffs have great symbolic value in Britain because they face towards continental Europe across the narrowest part of the English Channel (approximately 20 miles (32 km) between coasts), where invasions have historically threatened and against which
SECTION 50
#17328559836713120-528: The mineral gypsum ( calcium sulfate ). While gypsum-based blackboard chalk is the lowest cost to produce, and thus widely used in the developing world , use of carbonate-based chalk produces larger particles and thus less dust, and it is marketed as "dustless chalk". Coloured chalks, pastel chalks, and sidewalk chalk (shaped into larger sticks and often coloured), used to draw on sidewalks , streets, and driveways , are primarily made of gypsum rather than calcium carbonate chalk. Magnesium carbonate chalk
3180-557: The most famous is the extensive complex at Grimes Graves in Norfolk . Chalk was traditionally used in recreation. In field sports, such as tennis played on grass, powdered chalk was used to mark the boundary lines of the playing field or court. If a ball hits the line, a cloud of chalk or pigment dust will be visible. In recent years, powdered chalk has been replaced with titanium dioxide . In gymnastics, rock-climbing, weightlifting and tug of war , chalk — now usually magnesium carbonate —
3240-573: The point where Great Britain is closest to continental Europe – the Strait of Dover is approximately 20 miles (32 km) across. On a clear day the cliffs are visible from the French coast. The chalk cliffs of the Alabaster Coast of Normandy in France are part of the same geological system. The White Cliffs are at one end of the Kent Downs designated Area of Outstanding Natural Beauty . In 1999
3300-436: The small particles of chalk make it a substance ideal for cleaning and polishing. For example, toothpaste commonly contains small amounts of chalk, which serves as a mild abrasive . Polishing chalk is chalk prepared with a carefully controlled grain size, for very fine polishing of metals. French chalk (also known as tailor's chalk) is traditionally a hard chalk used to make temporary markings on cloth, mainly by tailors . It
3360-412: The stack, whilst new stacks develop. Some people desire to preserve the rocks and protect them from the erosive processes that formed Old Harry. The National Trust , who own the stacks in perpetuity, have experience in looking after the coast, and have found that "working with natural processes is the most sustainable approach". There are various stories about the naming of the rocks. One legend says that
3420-526: The sugary secretions from the larval "honey glands" and, in return, protect the larvae from predators and parasitoids, even going so far as to bury them at night. The larvae pupate in the upper soil, and continue to be protected by the ants, often in their nests, until the adults emerge in the spring or autumn. Similar in appearance, but more abundant, is the chalkhill blue , a chalk grassland specialist that can be seen in July and August. Threatened species include
3480-507: Was derived from the Latin albus (meaning 'white') as an allusion to the white cliffs. Dover Castle , the largest castle in England, was founded in the 11th century. It has been described as the "Key to England" owing to its defensive significance throughout history. The castle was founded by William the Conqueror in 1066 and rebuilt for Henry II , King John , and Henry III . This expanded
3540-446: Was named in honour of Dame Vera Lynn. Dover Museum was founded in 1836. Shelled from France in 1942 during the Second World War, the museum lost much of its collections, including nearly all its natural history collections. Much of the surviving material was left neglected in caves and other stores until 1946. In 1948 a temporary museum was opened and in 1991 a new museum of three storeys, built behind its original Victorian façade,
3600-523: Was opened. In 1999, a new gallery on the second floor centred on the Dover Bronze Age Boat was opened. Samphire Hoe Country Park is a nature reserve on a new piece of land created from the rock excavated during the construction of the Channel Tunnel . It covers a 74-acre (30 ha) site at the foot of Shakespeare Cliff , between Dover and Folkestone . There is an education shelter with
#670329