Bardon Hill Quarry is in north-west Leicestershire in the East Midlands where the rocks have been extracted for more than 400 years.
Bardon Hill rocks formed from a volcano in Precambrian times, about 570 million years ago.
The volcanic rocks are called andesite and its eruptions were similar to those recently witnessed on the island of Montserrat in the West Indies.
The modern quarry is about 800 m across.
It produces about three million tonnes of crushed rock per year, which is around 15 per cent of a normal year’s production for the whole of the UK.
This rock is valued for its properties when it is crushed and is used to build roads and for the foundations of buildings.
Bardon Hill is a Site of Special Scientific Interest (SSSI) because it has veins of quartz containing native copper and gold. It is also an unconformity: In the Triassic, the ancient land surface of Precambrian volcanic rocks had been eroded to form deep valleys called ‘wadis’ and these were infilled by red coloured desert sediments.
Further Bardon Quarry SSSI information is available from Natural England
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