The geology of Suffolk in eastern

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

largely consists of a rolling chalk plain overlain in the east by Neogene clays, sands and gravels and isolated areas of Palaeocene sands. A variety of superficial deposits originating in the last couple of million years overlie this 'solid geology'.

Cretaceous

The oldest rocks exposed at the surface in Suffolk are the mudstones and sandstones of the

Gault The Gault Formation is a geological formation of stiff blue clay deposited in a calm, fairly deep-water marine environment during the Lower Cretaceous Period (Upper and Middle Albian). It is well exposed in the coastal cliffs at Copt Point in ...

and

Upper Greensand Greensand or green sand is a sand or sandstone which has a greenish color. This term is specifically applied to shallow marine sediment that contains noticeable quantities of rounded greenish grains. These grains are called ''glauconies'' and c ...

formations which are to be found only in the extreme northwest of the county west of

Lakenheath Lakenheath is a village and civil parish in the West Suffolk district of Suffolk in eastern England. It has a population of 4,691 according to the 2011 Census, and is situated close to the county boundaries of both Norfolk and Cambridgeshire, ...

. Overlying these deposits and to their east are the rocks of the

Chalk Chalk 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. Ch ...

which are divided into the lower i.e. older Grey Chalk and the upper i.e. younger White Chalk.

Palaeogene

There are isolated pockets of Palaeocene sands and clays north of

Ipswich Ipswich () is a port town and borough in Suffolk, England, of which it is the county town. The town is located in East Anglia about away from the mouth of the River Orwell and the North Sea. Ipswich is both on the Great Eastern Main Line ...

and between there and Sudbury to the west. The clays of the early

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

Harwich Formation are widespread in the southeast of the county between Sudbury and

Orford Ness Orford Ness is a cuspate foreland shingle spit on the Suffolk coast in Great Britain, linked to the mainland at Aldeburgh and stretching along the coast to Orford and down to North Weir Point, opposite Shingle Street. It is divided from the m ...

Neogene

From Bury St Edmunds and Sudbury eastwards the Chalk is overlain by an extensive spread of

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

age 'crag' stretching to the

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

coast. Slightly older deposits known as Corralline Crag occur in the vicinity of

Aldeburgh Aldeburgh ( ) is a coastal town in the county of Suffolk, England. Located to the north of the River Alde. Its estimated population was 2,276 in 2019. It was home to the composer Benjamin Britten and remains the centre of the international Alde ...

and Orford.

Quaternary

A veneer of glacial till is widespread across Suffolk, dating from the Anglian glaciation. Sands and gravels of uncertain origin are common in the river valleys and the coastal plain whilst river terrace deposits have been mapped along the valleys of the rivers Stour,

Waveney Waveney may refer to: * River Waveney, a river that forms the boundary between Suffolk and Norfolk, England * Waveney District, a local government district in Suffolk, England * Waveney (UK Parliament constituency) * Waveney class lifeboat, a class ...

and

Gipping Gipping is a village and civil parish in the Mid Suffolk district of Suffolk in eastern England. Located around three miles north north-east of Stowmarket, in 2005 its population was 80. At the 2011 Census the population remained less than 100 ...

for instance. Estuarine and marine alluvium is spread across the eastern coastal zone whilst at the other side of the county areas of peat and lake clays, silts and sands occur.British Geological Survey 1:625,000 scale geological map ''Quaternary Map of the United Kingdom South'' 1st Edn. 1977

References

Geography of Suffolk Suffolk Suffolk {{geology-stub

Cretaceous

Palaeogene

Neogene

Quaternary

See also

References