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

china clay Kaolinite ( ) is a clay mineral, with the chemical composition Al2 Si2 O5( OH)4. It is an important industrial mineral. It is a layered silicate mineral, with one tetrahedral sheet of silica () linked through oxygen atoms to one octahedra ...

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 reduce their envir ...

that form a single Site of Special Scientific Interest (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 a ...

, noted for its biological 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.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. These waste materials are typically composed of shale, as well as smaller quant ...

s or vegetation-covered

granitic A granitoid is a generic term for a diverse category of coarse-grained igneous rocks that consist predominantly of quartz, plagioclase, and alkali feldspar. Granitoids range from plagioclase-rich tonalites to alkali-rich syenites and from quartz- ...

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 The Marchantiophyta () are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of ...

, 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, United Kingdom, the other being Godolphin Hill. They are approximately west of the town of Helston. The Plymouth chemist William Cookworthy mixed chi ...

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 extremely thin elastic plates. This characteristic is described as perfect basal cleavage. Mica is ...

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 the international conservation membership charity working to secure a world rich in wild plants and fungi. It is the only UK membership charity dedicated to conserving wild plants and fungi in their natural habitats and helping peo ...

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 Colonization, or colonisation, constitutes large-scale population movements wherein migrants maintain strong links with their, or their ancestors', former country – by such links, gain advantage over other inhabitants of the territory. When ...

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

References

{{SSSIs Cornwall biological 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