The Corton Formation is a series of deposits of

Middle Pleistocene The Chibanian, more widely known as the Middle Pleistocene (its previous informal name), is an Age (geology), age in the international geologic timescale or a Stage (stratigraphy), stage in chronostratigraphy, being a division of the Pleistocen ...

age found primarily along the coasts of

Suffolk Suffolk ( ) is a ceremonial county in the East of England and East Anglia. It is bordered by Norfolk to the north, the North Sea to the east, Essex to the south, and Cambridgeshire to the west. Ipswich is the largest settlement and the county ...

and

Norfolk Norfolk ( ) is a Ceremonial counties of England, ceremonial county in England, located in East Anglia and officially part of the East of England region. It borders Lincolnshire and The Wash to the north-west, the North Sea to the north and eas ...

in eastern

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

. The formation comprises two

stratigraphic Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithost ...

facies In geology, a facies ( , ; same pronunciation and spelling in the plural) is a body of rock with distinctive characteristics. The characteristics can be any observable attribute of rocks (such as their overall appearance, composition, or con ...

, an upper thicker fine to medium

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is usually defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural ...

which becomes a pebbly sand towards the base (around

Lowestoft Lowestoft ( ) is a coastal town and civil parish in the East Suffolk (district), East Suffolk district of Suffolk, England.OS Explorer Map OL40: The Broads: (1:25 000) : . As the List of extreme points of the United Kingdom, most easterly UK se ...

, the pebbly sands may be more extensive), and a lower

till image:Geschiebemergel.JPG, Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrounded by the matrix of finer material (silt and sand), and this characteristic, known as ''matrix support'', is d ...

comprising very

silt Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension (chemistry), suspension with water. Silt usually ...

y sandy

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impuriti ...

or clayey sand. The formation is named after Corton,

, the type locality for the

Anglian Stage The Anglian Stage is the name used in the British Isles for a middle Pleistocene glaciation. It precedes the Hoxnian Stage and follows the Cromerian Stage in the British Isles. It correlates to Marine Isotope Stage 12 (MIS 12), which started ab ...

of the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

in Britain.Jones R.L. & Keen D.H. (1993), ''Pleistocene Environments in the British Isles'', London: Chapman & Hall, The formation is overlain by the Lowestoft Formation. The till of the Corton Formation, known locally as the

Happisburgh Happisburgh () is a village civil parish in the English county of Norfolk. The village is on the coast, to the east of a north–south road, the B1159 from Bacton on the coast to Stalham. It is a nucleated village. The nearest substantial ...

Till and the Corton Till, was formerly believed to have been deposited by a

Scandinavia Scandinavia is a subregion#Europe, subregion of northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. ''Scandinavia'' most commonly refers to Denmark, Norway, and Sweden. It can sometimes also ...

n ice sheet of Anglian age. However recent investigations indicate deposition by an

ice sheet In glaciology, an ice sheet, also known as a continental glacier, is a mass of glacier, glacial ice that covers surrounding terrain and is greater than . The only current ice sheets are the Antarctic ice sheet and the Greenland ice sheet. Ice s ...

which flowed southwards into north-east

East Anglia East Anglia is an area of the East of England, often defined as including the counties of Norfolk, Suffolk and Cambridgeshire, with parts of Essex sometimes also included. The name derives from the Anglo-Saxon kingdom of the East Angles, ...

from central and southern

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

, eroding and transporting materials derived from outcrops in these areas and from eastern

and the western margins of the southern

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

Basin. This indicates that the long-held assumption that the tills of the Corton Formation were deposited by a Scandinavian ice sheet is erroneous and that they were instead deposited by Scottish ice. More recently still it has been suggested that the Happisburgh Till may be in fact be pre-Anglian. This is from indirect evidence, namely the discovery of clasts of re-worked till in the deposits of the

Bytham River The Bytham River is said to have been one of the great Pleistocene rivers of central and eastern England until it was destroyed by the advancing ice sheets of the Anglian Glaciation around 450,000 years ago. The river is named after Castle By ...

that are overlain by Anglian material (, discussed online in ). The sands of the Corton Formation have been interpreted as being deposited in an ice-dammed lake, possibly the one which overflowed to breach the chalk ridge of the Weald-Artois Anticline and open the

English Channel The English Channel, also known as the Channel, is an arm of the Atlantic Ocean that separates Southern England from northern France. It links to the southern part of the North Sea by the Strait of Dover at its northeastern end. It is the busi ...

References

Geology of Norfolk Geography of Suffolk Geologic formations of the United Kingdom Pleistocene {{UK-geologic-formation-stub