St Austell Clay Pits, (Cornwall, England, UK,) are a group of locations within active

china clay Kaolinite ( ; also called kaolin) is a clay mineral, with the chemical composition aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4. It is a layered silicate mineral, with one tetrahedron, tetrahedral sheet of silica () linked through oxygen ...

quarries A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to manage their safet ...

that form a single

Site of Special Scientific Interest A Site of Special Scientific Interest (SSSI) in Great Britain, or an Area of Special Scientific Interest (ASSI) in the Isle of Man and Northern Ireland, is a conservation designation denoting a protected area in the United Kingdom and Isle ...

(SSSI) and

Special Area of Conservation A special area of conservation (SAC) is defined in the European Union's Habitats Directive (92/43/EEC), also known as the ''Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora''. They are to protect the 220 habitats and ap ...

, noted for its

biological Biology is the scientific study of life and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, origin, evolution, and distribution of ...

characteristics. In particular, the site is known for the rare western rustwort, a plant that grows only at two other sites in the UK.

Geography

The SSSI, notified in 2000, comprises three separate sites that are all about north of the town of

St Austell Saint Austell (, ; ) is a town in Cornwall, England, United Kingdom, south of Bodmin and west of the border with Devon. At the 2021 Census in the United Kingdom, census it had a population of 20,900. History St Austell was a village centred ...

.Ordnance Survey: Landranger map sheet 200 ''Newquay & Bodmin'' They all lie within china clay workings which are still active and are situated on either pits,

spoil tip A spoil tip (also called a boney pile, culm bank, gob pile, waste tip or bing) is a pile built of accumulated ''spoil'' – waste material removed during mining. Spoil tips are not formed of slag, but in some areas, such as England and Wales, ...

s or vegetation-covered

granitic A granitoid is a broad term referring to a diverse group of coarse-grained igneous rocks that are widely distributed across the globe, covering a significant portion of the Earth's exposed surface and constituting a large part of the continental ...

debris. The combined site is also designated a

Special Areas of Conservation A special area of conservation (SAC) is defined in the European Union's Habitats Directive (92/43/EEC), also known as the ''Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora''. They are to protect the 220 habitats and ap ...

(SAC).

Wildlife and ecology

The SSSI owes its importance to a rare

liverwort Liverworts are a group of non-vascular land plants forming the division Marchantiophyta (). They may also be referred to as hepatics. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry ...

, the western rustwort ('' Marsupella profunda''), which in the UK can be found only at this site and at two others: Lower Bostraze and Leswidden and

Tregonning Hill Tregonning Hill is the westerly of two granite hills overlooking Mount's Bay in west Cornwall, England, United Kingdom, the other being Godolphin Hill. They are approximately west of the town of Helston. The Plymouth chemist William Cookworthy ...

SSSIs, both within Cornwall, to the west. It is mostly found growing in moist conditions on

micaceous Micas ( ) are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily be split into fragile elastic plates. This characteristic is described as ''perfect basal cleavage''. Mica is co ...

or clay waste substrates with no or little sloping, as well as on soft or crumbling granite rocks. Lansalon Pit - geograph

Owing to the presence of the rare western rustwort,

Plantlife Plantlife is a wild plant conservation charity. , it manages 24 nature reserves around the United Kingdom. HM King Charles III is patron of the charity. History Plantlife was founded in 1989. Its first president was Professor David Bellamy ...

has designated a large area of active and disused mine workings in the St Austell area as an

Important Plant Area Important Plant Areas (IPA) is a programme set up in the UK, by the organisation Plantlife, to provide a framework for identifying and maintaining the richest sites for plant life, possibly within existing protected areas; though the protection of ...

, with the same name as the SSSI. This area includes all the SSSI sites, as well as many others. It is thought that the protected areas will act as a source for

colonisation 475px, Map of the year each country achieved List of sovereign states by date of formation, independence. Colonization (British English: colonisation) is a process of establishing occupation of or control over foreign territories or peoples f ...

for the western rustwort to other locations in the surrounding china clay area.

References

{{DEFAULTSORT:Saint Austell Clay Pits Sites of Special Scientific Interest in Cornwall Sites of Special Scientific Interest notified in 2000 Special Areas of Conservation in Cornwall St Austell

Geography

Wildlife and ecology

See also

References