Holwell Quarries

Site of Special Scientific Interest
Location within Somerset
Location	Somerset
Grid reference	ST726450
Coordinates	51°12′13″N 2°23′37″W / 51.20355°N 2.39357°W / 51.20355; -2.39357
Interest	Geological
Area	1.3 hectares (0.013 km2; 0.0050 sq mi)
Notification	1952 (1952)
Natural England website

Holwell Quarries (grid reference ST726450) is a 1.3-hectare (3.2-acre) geological Site of Special Scientific Interest at Holwell near Nunney on the Mendip Hills in Somerset, notified in 1952.

Holwell Quarries represent an internationally important geological locality. A comprehensive assemblage of Triassic (including Rhaetic), Lower Jurassic and Middle Jurassic fissure fillings are well displayed. The Rhaetic fissure fillings have yielded the richest assemblage of vertebrate faunas known from the British Triassic. Fissure deposits have also yielded 8 or 9 genera of Reptiles: a Crocodilian, a Placodont (the first record in Britain of this sub-order), and the dinosaurs Thecodontosaurus and Palaeosaurus. The Lower Jurassic fissure fillings yield ammonites and brachiopods which are important in dating these deposits.

• Quarries of the Mendip Hills

• English Nature citation sheet for the site (accessed 10 August 2006)

• English Nature website (SSSI information)