The Dorset Downs are an area of
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 ...
downland
Downland, chalkland, chalk downs or just downs are areas of open chalk hills, such as the North Downs. This term is used to describe the characteristic landscape in southern England where chalk is exposed at the surface. The name "downs" is deriv ...
in the centre of the county
Dorset
Dorset ( ; archaically: Dorsetshire , ) is a county in South West England on the English Channel coast. The ceremonial county comprises the unitary authority areas of Bournemouth, Christchurch and Poole and Dorset. Covering an area of , ...
in south west
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 ...
. The downs are the most western part of a larger
chalk formation
The Chalk Group (often just called the Chalk) is the lithostratigraphic unit (a certain number of rock strata) which contains the Upper Cretaceous limestone succession in southern and eastern England. The same or similar rock sequences occur a ...
which also includes (from west to east)
Cranborne Chase,
Salisbury Plain,
Hampshire Downs
The Hampshire Downs form a large area of downland in central southern England, mainly in the county of Hampshire but with parts in Berkshire and Wiltshire. They are part of a belt of chalk downland that extends from the South Downs in the southe ...
,
Chiltern Hills,
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. Much of the North Downs comprises two Areas of Outstanding Natural Beauty (AONBs): the Surrey Hills a ...
and
South Downs
The South Downs are 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, in the Eastbourne Downland Estate, East Sussex, in the eas ...
.
[''Uplift, Erosion and Stability: Perspectives on Long-term Landscape Development''](_blank)
ed. by Smith, Bernard J., Whalley Wilfred B. and Warke Patricia A. (1999), Geological Society Special Publication No. 162, Bath. Accessed on 3 Apr 2013.
Physical geography
The Dorset Downs are bounded on the north, along the steep
scarp face, by the
Blackmore Vale
The Blackmore Vale (; less commonly spelt ''Blackmoor'') is a vale, or wide valley, in north Dorset, and to a lesser extent south Somerset and southwest Wiltshire in southern England.
Geography
The vale is part of the Stour valley, part of th ...
, a large
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 ...
and
limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...
valley
A valley is an elongated low area often running between hills or mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams ove ...
. On the east, the Downs were once, thousands of years ago, continuous with Cranborne Chase, but the
River Stour now cuts a valley between them, which is the location of
Blandford Forum and the eastern boundary of the downs. From the northern scarp face, the hills dip gently southwards before the chalk disappears beneath the
Bagshot Beds
In geology, the Bagshot Beds are a series of sands and clays of shallow-water origin, some being fresh-water, some marine. They belong to the upper Eocene formation of the London and Hampshire basins, in England and derive their name from Bags ...
which form the heathlands of the county, between
Dorchester and
Wareham. South of the
River Frome, the chalk reappears in a narrower strip, forming coastal cliffs east of
Weymouth and, further east, the steep ridge of the
Purbeck Hills
The Purbeck Hills, also called the Purbeck Ridge or simply the Purbecks, are a ridge of chalk downs in Dorset, England. It is formed by the structure known as the Purbeck Monocline. The ridge extends from Lulworth Cove in the west to Old H ...
. This southerly strip of the visible chalk (sometimes referred to as the South Dorset Downs or South Dorset Ridgeway) continues westwards behind Weymouth, and rejoins the main body of the downs at their western extremity at
Eggardon Hill
Eggardon Hill is a prehistoric hillfort on a hill in Dorset, England. It is located on chalk uplands approximately four miles to the east of the town of Bridport.
The Hill
Eggardon Hill stands above sea level and is classified as a Hump (hi ...
. In the west the chalk dips down under
marl.
Together with Cranborne Chase, the Dorset Downs have been designated as
National Character Area 134 by
Natural England
Natural England is a non-departmental public body in the United Kingdom sponsored by the Department for Environment, Food and Rural Affairs. It is responsible for ensuring that England's natural environment, including its land, flora and fauna, ...
, the UK Government's advisor on the natural environment. In Dorset this area is bounded by the
Dorset Heaths and
Weymouth Lowlands to the south, the
Marshwood and Powerstock Vales to the west and the
Blackmore Vale
The Blackmore Vale (; less commonly spelt ''Blackmoor'') is a vale, or wide valley, in north Dorset, and to a lesser extent south Somerset and southwest Wiltshire in southern England.
Geography
The vale is part of the Stour valley, part of th ...
to the north.
[''Dorset Downs and Cranborne Chase''](_blank)
at www.naturalengland.org.uk. Accessed on 3 Apr 2013.
The main land uses on the downs are
arable agriculture
Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people t ...
,
woodland
A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ''plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (se ...
and
calcareous grassland
Calcareous grassland (or alkaline grassland) is an ecosystem associated with thin basic soil, such as that on chalk and limestone downland. Plants on calcareous grassland are typically short and hardy, and include grasses and herbs such as clover. ...
, a
habitat
In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...
which is growing as farmers are encouraged to
set aside land with
subsidies
A subsidy or government incentive is a form of financial aid or support extended to an economic sector (business, or individual) generally with the aim of promoting economic and social policy. Although commonly extended from the government, the ter ...
. Chalk is a rough rock and the Dorset Downs hold a large
water table
The water table is the upper surface of the zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with water. It can also be simply explained as the depth below which the ground is saturated.
T ...
which acts as a
reservoir
A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation.
Reservoirs can be created in a number of ways, including contro ...
of drinking water for much of the county. This property of chalk also means there are many seasonal rivers, called
winterbournes, that flow depending upon the level of the water table.
Hills
*
Bulbarrow Hill (274 m), site of Rawlsbury camp and the highest hill in the Downs.
*
Telegraph Hill (267 m)
*
Lyscombe Hill (262 m)
*
Watts Hill (261 m)
*
Bell Hill (258 m)
*
Eggardon Hill
Eggardon Hill is a prehistoric hillfort on a hill in Dorset, England. It is located on chalk uplands approximately four miles to the east of the town of Bridport.
The Hill
Eggardon Hill stands above sea level and is classified as a Hump (hi ...
(252 m), also the western extremity of the
South Dorset Downs
*
Toller Down (252 m)
*
Ball Hill
Ball Hill is an area within the Stoke district of Coventry, West Midlands, England. It is to the east of Coventry city centre.
Walsgrave Road is the main street that runs through Ball Hill, which is a name that primarily defines the shoppin ...
(251 m)
*
Dogbury Hill (248 m)
*
Beaminster Down
At 244 metres, Beaminster Down is one of the highest hills in West Dorset, England.
Location
Beaminster Down is common land on the Dorset Downs and overlooks the steep scarp slope above the town of Beaminster, which is about a mile and a half ...
(244 m)
*
Shillingstone Hill (223 m), a densely wooded scarp face with a large quarry.
*
Rampisham Down (219 m)
*
Hambledon Hill (192 m) and
Hod Hill (143 m), two outliers of
Cranborne Chase, separated from the Downs by the
River Stour.
Fauna
The downs are the native home to the
Dorset Down sheep
Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to domesticated ...
.
Places of interest
*
Blandford Forest
*
Cerne valley, including
Cerne Abbas Giant.
*
Dorsetshire Gap, a steep valley.
*
Milton Abbas, 18th-century planned estate village and museum.
*
Minterne Magna, ''Rhododendron'' garden at Minterne House.
*
Nettlecombe Tout hill fort.
*
Ringmoor settlement and field system.
See also
*
Bowerchalke - geological profile of a Lower Greensand
inlier on the chalklands of Cranborne Chase
References
{{Reflist
Hills of Dorset
Natural regions of Dorset
Geology of Dorset