Southern England Chalk Formation
Encyclopedia
Chalk Formation
The Chalk Group is a lithostratigraphic unit in the northwestern part of Europe. It is characterised by thick deposits of chalk, a soft porous white limestone, deposited in a marine environment during the Upper Cretaceous period.Chalk is a limestone that consists of coccolith biomicrite...
of Southern England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
is a system of chalk
Chalk
Chalk is a soft, white, porous sedimentary rock, a form of limestone composed of the mineral calcite. Calcite is calcium carbonate or CaCO3. It forms under reasonably deep marine conditions from the gradual accumulation of minute calcite plates shed from micro-organisms called coccolithophores....
downland
Downland
A downland is an area of open chalk hills. This term is especially used to describe the chalk countryside in southern England. Areas of downland are often referred to as Downs....
in the south of England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
. The formation is perhaps best known for Salisbury Plain
Salisbury Plain
Salisbury Plain is a chalk plateau in central southern England covering . It is part of the Southern England Chalk Formation and largely lies within the county of Wiltshire, with a little in Hampshire. The plain is famous for its rich archaeology, including Stonehenge, one of England's best known...
, the location of Stonehenge
Stonehenge
Stonehenge is a prehistoric monument located in the English county of Wiltshire, about west of Amesbury and north of Salisbury. One of the most famous sites in the world, Stonehenge is composed of a circular setting of large standing stones set within earthworks...
, the Isle of Wight
Isle of Wight
The Isle of Wight is a county and the largest island of England, located in the English Channel, on average about 2–4 miles off the south coast of the county of Hampshire, separated from the mainland by a strait called the Solent...
and the twin ridgeways of the North Downs
North Downs
The North Downs are a ridge of chalk hills in south east England that stretch from Farnham in Surrey to the White Cliffs of Dover in Kent. The North Downs lie within two Areas of Outstanding Natural Beauty , the Surrey Hills and the Kent Downs...
and South Downs
South Downs
The South Downs is a range of chalk hills that extends for about across the south-eastern coastal counties of England from the Itchen Valley of Hampshire in the west to Beachy Head, near Eastbourne, East Sussex, in the east. It is bounded on its northern side by a steep escarpment, from whose...
.
Geography
Surrey
Surrey is a county in the South East of England and is one of the Home Counties. The county borders Greater London, Kent, East Sussex, West Sussex, Hampshire and Berkshire. The historic county town is Guildford. Surrey County Council sits at Kingston upon Thames, although this has been part of...
and Kent
Kent
Kent is a county in southeast England, and is one of the home counties. It borders East Sussex, Surrey and Greater London and has a defined boundary with Essex in the middle of the Thames Estuary. The ceremonial county boundaries of Kent include the shire county of Kent and the unitary borough of...
, and the South to Sussex
Sussex
Sussex , from the Old English Sūþsēaxe , is an historic county in South East England corresponding roughly in area to the ancient Kingdom of Sussex. It is bounded on the north by Surrey, east by Kent, south by the English Channel, and west by Hampshire, and is divided for local government into West...
. Each forms a well-defined long range springing from the chalk area of Dorset
Dorset
Dorset , is a county in South West England on the English Channel coast. The county town is Dorchester which is situated in the south. The Hampshire towns of Bournemouth and Christchurch joined the county with the reorganisation of local government in 1974...
and Hampshire
Hampshire
Hampshire is a county on the southern coast of England in the United Kingdom. The county town of Hampshire is Winchester, a historic cathedral city that was once the capital of England. Hampshire is notable for housing the original birthplaces of the Royal Navy, British Army, and Royal Air Force...
, to which, though broken up into a great number of short ranges and groups of hills, the general name of the Western Downs is given. The Downs enclose the rich district of the Weald
Weald
The Weald is the name given to an area in South East England situated between the parallel chalk escarpments of the North and the South Downs. It should be regarded as three separate parts: the sandstone "High Weald" in the centre; the clay "Low Weald" periphery; and the Greensand Ridge which...
, where the chalk has eroded to form a much flatter landscape.
In Wiltshire
Wiltshire
Wiltshire is a ceremonial county in South West England. It is landlocked and borders the counties of Dorset, Somerset, Hampshire, Gloucestershire, Oxfordshire and Berkshire. It contains the unitary authority of Swindon and covers...
is Salisbury Plain
Salisbury Plain
Salisbury Plain is a chalk plateau in central southern England covering . It is part of the Southern England Chalk Formation and largely lies within the county of Wiltshire, with a little in Hampshire. The plain is famous for its rich archaeology, including Stonehenge, one of England's best known...
, the Wiltshire Downs and Cranborne Chase
Cranborne Chase
Cranborne Chase is a Chalk plateau in central southern England, straddling the counties Dorset, Hampshire and Wiltshire. The plateau is part of the English Chalk Formation and is adjacent to Salisbury Plain and the West Wiltshire Downs in the north, the Dorset Downs to the south west and the...
, all three famous for their archaeology
Archaeology
Archaeology, or archeology , is the study of human society, primarily through the recovery and analysis of the material culture and environmental data that they have left behind, which includes artifacts, architecture, biofacts and cultural landscapes...
, and it was on these downs that Augustus Pitt Rivers
Augustus Pitt Rivers
Lieutenant-General Augustus Henry Lane-Fox Pitt Rivers was an English army officer, ethnologist, and archaeologist. He was noted for his innovations in archaeological methods, and in the museum display of archaeological and ethnological collections.-Life and career:Born Augustus Henry Lane-Fox at...
developed the methods of modern archaeological field work in the 19th century. The Berkshire Downs
Berkshire Downs
The Berkshire Downs are a range of chalk downland hills in southern England, part of the North Wessex Downs Area of Outstanding Natural Beauty...
and White Horse Hills adjoin the northernmost part of this formation.
To the north of these downs, mostly in Buckinghamshire
Buckinghamshire
Buckinghamshire is a ceremonial and non-metropolitan home county in South East England. The county town is Aylesbury, the largest town in the ceremonial county is Milton Keynes and largest town in the non-metropolitan county is High Wycombe....
, are the Chiltern Hills
Chiltern Hills
The Chiltern Hills form a chalk escarpment in South East England. They are known locally as "the Chilterns". A large portion of the hills was designated officially as an Area of Outstanding Natural Beauty in 1965.-Location:...
, running north east.
At the far south west of the formation are the Dorset Downs
Dorset Downs
The Dorset Downs are an area of Chalk downland in the centre of the county Dorset in south west England. The downs are the most western part of a larger Chalk Formation which also includes Cranborne Chase, Salisbury Plain, Hampshire Downs, Chiltern Hills, North Downs and South Downs.The Dorset...
, notable for their rich Roman
Ancient Rome
Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....
and pre-Roman archaeology, including a number of Iron Age
Iron Age
The Iron Age is the archaeological period generally occurring after the Bronze Age, marked by the prevalent use of iron. The early period of the age is characterized by the widespread use of iron or steel. The adoption of such material coincided with other changes in society, including differing...
hill fort
Hill fort
A hill fort is a type of earthworks used as a fortified refuge or defended settlement, located to exploit a rise in elevation for defensive advantage. They are typically European and of the Bronze and Iron Ages. Some were used in the post-Roman period...
s. The Purbeck Hills
Purbeck Hills
The Purbeck Hills and South Dorset Downs are a ridge of chalk downs in Dorset, England. The hills extend from the Dorset Downs west of Dorchester, where the River Frome begins to form a valley dividing them from the larger area of downland to the north. The ridge then runs east through the Isle...
fork from the Dorset Downs to run on, or near the Jurassic Coast
Jurassic Coast
The Jurassic Coast is a World Heritage Site on the English Channel coast of southern England. The site stretches from Orcombe Point near Exmouth in East Devon to Old Harry Rocks near Swanage in East Dorset, a distance of ....
in south east Dorset, where they form part of Lulworth Cove
Lulworth Cove
Lulworth Cove is a cove near the village of West Lulworth, on the Jurassic Coast World Heritage Site in Dorset, southern England. The cove is one of the world's finest examples of such a landform, and is a tourist location with over 1 million visitors a year...
, White Nothe
White Nothe
White Nothe is a chalk headland on the English Channel coast at the eastern end of Ringstead Bay, east of Weymouth in Dorset, England. The area is well-known for its geology and fossils...
and Old Harry Rocks
Old Harry Rocks
The Old Harry Rocks are two chalk sea stacks located at Handfast Point, on the Isle of Purbeck in Dorset, southern England.- Location :Old Harry Rocks lie directly east of Studland, about 4 kilometres northeast of Swanage, and about 10 kilometres south of the large towns of Poole and...
, some of the many famous landforms on England's only natural World Heritage Site
World Heritage Site
A UNESCO World Heritage Site is a place that is listed by the UNESCO as of special cultural or physical significance...
.
Smooth convex curves are characteristic of the Downs; their graceful and striking outline gives them an importance in the landscape in excess of their actual height; their flanks are well wooded, their summits covered with close springy turf.
Where the chalk hills meet the sea there are white cliffs such as the White Cliffs of Dover
White cliffs of Dover
The White Cliffs of Dover are cliffs which form part of the British coastline facing the Strait of Dover and France. The cliffs are part of the North Downs formation. The cliff face, which reaches up to , owes its striking façade to its composition of chalk accentuated by streaks of black flint...
, Seven Sisters
Seven Sisters, Sussex
The Seven Sisters are a series of chalk cliffs by the English Channel. They form part of the South Downs in East Sussex, between the towns of Seaford and Eastbourne in southern England. They are within the Seven Sisters Country Park...
and The Needles
The Needles
The Needles is a row of three distinctive stacks of chalk that rise out of the sea off the western extremity of the Isle of Wight, England, close to Alum Bay. The Needles lighthouse stands at the end of the formation...
on the Isle of Wight
Isle of Wight
The Isle of Wight is a county and the largest island of England, located in the English Channel, on average about 2–4 miles off the south coast of the county of Hampshire, separated from the mainland by a strait called the Solent...
The chalk would once have extended across the English Channel
English Channel
The English Channel , often referred to simply as the Channel, is an arm of the Atlantic Ocean that separates southern England from northern France, and joins the North Sea to the Atlantic. It is about long and varies in width from at its widest to in the Strait of Dover...
and similar cliff features can be found on the French coast.
Geology
The Chalk FormationChalk Formation
The Chalk Group is a lithostratigraphic unit in the northwestern part of Europe. It is characterised by thick deposits of chalk, a soft porous white limestone, deposited in a marine environment during the Upper Cretaceous period.Chalk is a limestone that consists of coccolith biomicrite...
was laid down under the sea during the Upper Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
period, and was later uplifted at around the same time as the Alps
Alps
The Alps is one of the great mountain range systems of Europe, stretching from Austria and Slovenia in the east through Italy, Switzerland, Liechtenstein and Germany to France in the west....
were formed. In south-east England, the chalk deposits were formed into an elongated dome
Dome
A dome is a structural element of architecture that resembles the hollow upper half of a sphere. Dome structures made of various materials have a long architectural lineage extending into prehistory....
, with the long axis in a roughly east-west direction. Erosion along the line of this axis removed the central part of the chalk and revealed the underlying Weald
Weald
The Weald is the name given to an area in South East England situated between the parallel chalk escarpments of the North and the South Downs. It should be regarded as three separate parts: the sandstone "High Weald" in the centre; the clay "Low Weald" periphery; and the Greensand Ridge which...
en deposits. The remaining chalk forms the characteristic escarpment
Escarpment
An escarpment is a steep slope or long cliff that occurs from erosion or faulting and separates two relatively level areas of differing elevations.-Description and variants:...
s of the North
North Downs
The North Downs are a ridge of chalk hills in south east England that stretch from Farnham in Surrey to the White Cliffs of Dover in Kent. The North Downs lie within two Areas of Outstanding Natural Beauty , the Surrey Hills and the Kent Downs...
and South Downs
South Downs
The South Downs is a range of chalk hills that extends for about across the south-eastern coastal counties of England from the Itchen Valley of Hampshire in the west to Beachy Head, near Eastbourne, East Sussex, in the east. It is bounded on its northern side by a steep escarpment, from whose...
.
Stronger uplift and folding occurred in Dorset
Dorset
Dorset , is a county in South West England on the English Channel coast. The county town is Dorchester which is situated in the south. The Hampshire towns of Bournemouth and Christchurch joined the county with the reorganisation of local government in 1974...
and the Isle of Wight
Isle of Wight
The Isle of Wight is a county and the largest island of England, located in the English Channel, on average about 2–4 miles off the south coast of the county of Hampshire, separated from the mainland by a strait called the Solent...
, where the chalk strata are almost vertical in some places, such as The Needles
The Needles
The Needles is a row of three distinctive stacks of chalk that rise out of the sea off the western extremity of the Isle of Wight, England, close to Alum Bay. The Needles lighthouse stands at the end of the formation...
.