Geological Nature Reserves

The Cornwall Wildlife Trust has two geological nature reserves: St Erth Pits and Tresayes Quarry, and several more reserves with some geological interest.

Geological nature reserves are sites that have been acquired by the Cornwall Geoconservation Group through Cornwall Wildlife Trust and are important for geological and biological reasons. They illustrate the close links that exist between the geology of an area and its wildlife habitats.

St Erth Pits Nature Reserve

St Erth Pits were originally worked for moulding sand and fossiliferous clay of Pliocene age. The St Erth Pits Nature Reserve is of national importance and this is recognised by its designation as a Site of Special Scientific Interest (SSSI). It provides evidence of the climate and geography of this part of west Cornwall some two million years ago. An information board about the site can be found on the wall of the Star Inn in the village of St Erth and a St Erth Pits Nature Reserve information leaflet is also available.

Tresayes Quarry Nature Reserve

Tresayes Quarry, also known as ‘the Glass Mine’, is an old feldspar working in a pegmatite vein in the metamorphic aureole of the St Austell granite. The feldspar produced was used in the glass making industry and is reputed to have been used to make Spitfire windscreens during the war.
The nature reserve has on-site interpretation panels that tell more about the exciting geology and history of this quarry. The site also features in the Roche Rock and Tresayes Trail leaflet. These can be viewed or downloaded at the bottom of this page.

Other nature reserves with geological interest

Several other Cornwall Wildlife Trust nature reserves have some geological interest. These include Baker's Pit near St Ives, Churchtown Farm Community Nature Reserve in Saltash, Ropehaven Cliffs near St Austell and North Predannack Downs and Windmill Farm on The Lizard.


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Tresayes Panel_1.jpg272.97 KB
Tresayes Panel_2.jpg292.8 KB
cornwall_wildlife_trust_roche_rock_tresayes_trail_leaflet.pdf2.26 MB
roche_rock_panel.pdf809.39 KB