The Vale of Kent, located in

Kent Kent is a county in South East England and one of the home counties. It borders Greater London to the north-west, Surrey to the west and East Sussex to the south-west, and Essex to the north across the estuary of the River Thames; it faces ...

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 ...

, is the name given to the broad clay

vale A vale is a type of valley. Vale may also refer to: Places Georgia * Vale, Georgia, a town in the Samtskhe-Javakheti region Norway * Våle, a historic municipality Portugal * Vale (Santa Maria da Feira), a former civil parish in the municipali ...

between the

Greensand Ridge The Greensand Ridge, also known as the Wealden Greensand is an extensive, prominent, often wooded, mixed greensand/sandstone escarpment in south-east England. Forming part of the Weald, a former dense forest in Sussex, Surrey and Kent, it runs ...

and the High Weald. The area is drained by a number of

rivers A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...

, including the Beult, Eden,

Medway Medway is a unitary authority district and conurbation in Kent, South East England. It had a population of 278,016 in 2019. The unitary authority was formed in 1998 when Rochester-upon-Medway amalgamated with the Borough of Gillingham to for ...

, Stour and

River Teise The River Teise ( , ) is a tributary of the River Medway in Kent, England. Course The source of the Teise is in Dunorlan Park in Tunbridge Wells. From there the river flows eastwards past Bayham Abbey and then through Lamberhurst. downstream ...

. Principal settlements in the Vale include Ashford and

Tonbridge Tonbridge ( ) is a market town in Kent, England, on the River Medway, north of Royal Tunbridge Wells, south west of Maidstone and south east of London. In the administrative borough of Tonbridge and Malling, it had an estimated population ...

Geology

The Weald is the eroded remains of a geological structure, an

anticline In structural geology, an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex up in which the hinge or crest is the ...

, a dome of layered

Lower Cretaceous Lower may refer to: *Lower (surname) *Lower Township, New Jersey *Lower Receiver (firearms) *Lower Wick Lower Wick is a small hamlet located in the county of Gloucestershire, England. It is situated about five miles south west of Dursley, eight ...

rock Rock most often refers to: * Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids * Rock music, a genre of popular music Rock or Rocks may also refer to: Places United Kingdom * Rock, Caerphilly, a location in Wales ...

s cut through by

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...

to expose the layers as

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

ridges and

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...

valleys. The oldest rocks exposed at the centre of the anticline are correlated with the

Purbeck Beds The Purbeck Group is an Upper Jurassic to Lower Cretaceous lithostratigraphic group (a sequence of rock strata) in south-east England. The name is derived from the district known as the Isle of Purbeck in Dorset where the strata are exposed in the ...

of the

Upper Jurassic The Late Jurassic is the third epoch of the Jurassic Period, and it spans the geologic time from 163.5 ± 1.0 to 145.0 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic strata.Owen 1987. In European lithostratigraphy, the name ...

. Above these, the Cretaceous rocks, include the Wealden Group of alternating sands and clays - the Ashdown Sand,

Wadhurst Clay The Wadhurst Clay Formation is a geological unit which forms part of the Wealden Group and the middle part of the now unofficial Hastings Beds. These geological units make up the core of the geology of the High Weald in the English counties of West ...

, Tunbridge Wells Sand (collectively known as the Hastings Beds) and the

Weald Clay Weald Clay or the Weald Clay Formation is a Lower Cretaceous sedimentary rock unit underlying areas of South East England, between the North and South Downs, in an area called the Weald Basin. It is the uppermost unit of the Wealden Group of ro ...

. The Wealden Group is overlain by the

Lower Greensand The Lower Greensand Group is a geological unit present across large areas of Southern England. It was deposited during the Aptian and Albian stages of the Early Cretaceous. It predominantly consists of sandstone and unconsolidated sand that were ...

and the Gault Formation, consisting of the

Gault Clay 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 the

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 co ...

.Gallois R.W. & Edmunds M.A. (4th Ed 1965), ''The Wealden District'', British Regional Geology series, British Geological Survey, The rocks of the central part of the anticline include hard sandstones, and these form hills now called the ''High Weald''. The peripheral areas are mostly of softer sandstones and clays and these form the gentler rolling landscape of ''Low Weald'', of which the Vale of Kent is a part. The Weald-Artois Anticline continues some further south-eastwards under the

Straits of Dover The Strait of Dover or Dover Strait (french: Pas de Calais - ''Strait of Calais''), is the strait at the narrowest part of the English Channel, marking the boundary between the Channel and the North Sea, separating Great Britain from continent ...

, and includes the Boulonnais of

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

References

{{Coord, 51.2024, 0.5177, display=title, format=dms Valleys of Kent Ashford, Kent Tonbridge and Malling Cretaceous England