The Cornubian Orefield lies within a peninsula in the southwest of England. It covers the whole of county of Cornwall and part of the county of Devon from Land’s End to Dartmoor, a distance of some 150 km.

 

The metalliferous deposits found in this world famous orefield have been exploited from the Bronze Age, some 2500 years B.C., to the end of the last century.

Bronze palstave
South Crofty Mine

 

Remains of the most intense period of activity are present in the form of engine houses and spoil tips, some of which lie in spectacular settings.

Crowns engine houses

19th century mining landscape

During the later part of the 18th and into the 19th century it was the most important centre of mining in the world. Not only producing ores of economic importance it also produced magnificent mineral specimens. It was during this time that the south west of England was at the cutting edge of metal mining technology, the science of ore geology and mineralogy, and many terms used in mining today are derived from Cornish words.

William Pryce

Liroconite


 

The geological importance of the region was promoted by the establishment of the Royal Geological Society of Cornwall in 1814, one of whose members was Sir Humphry Davy, and later mining schools, the most famous of which is the Camborne School of Mines that survives to this day.

Royal Geological Society of Cornwall
Sir Humphry Davy

 

 

Although world renown for the production of tin ores in the form of cassiterite or tin oxide (SnO2), it has produced a substantial tonnage of copper as well as eleven other metals/metalloid and other minerals.

Cassiterite (tin ore)
Chalcopyrite (copper ore)

 

Metal/Mineral
Estimated total production
Tin (metal)
2,500,000
Copper (metal)
2,000,000
Arsenic (As2O3)
250,000
Lead (metal)
250,000
Zinc (metal)
25,000
Tungsten (WO3)
5,600
Silver (ore)
2,000
Silver (from lead)
235
Uranium (ores)
2,000
Antimony (ores)
1,000
Cobalt and Nickel (ores)
500
Iron Ore
2,000,000*
Manganese
100,000*
Barytes
500,000
Fluorspar
10,000
Pyrite
150,000
China Clay
1000,000,000

The orefield has also produced small unrecorded quantities of gold and radium.
* Most iron and manganese ores were won from deposits not related to the granite-related mineralized system.

Bromley, 1989.

Diamond drilling
 

Geological research of the district dates back over two hundred years. De la Beche first mapped the region in the 1830s; this was the first state-funded geological survey. In the last 30 years that research has been driven by recent exploration and exploitation of the orefield, which commenced in the 1960s.
 
Wheal Jane Mine

Although the first collapse occurred at the end of the 19th century, mining finally ceased in 1998 with the closure of South Crofty Mine. The price of tin had fallen in 1985 due to a collapse of the International Tin Council. In the 19th century it had led to mass emigration, and once again skilled miners at the end of the 20th century had to travel abroad to sell their skills.

Mining has however, left a legacy of contamination in the form of derelict industrial land, soil and water contamination as well as hazards from collapsing underground mine workings.
Levant mine site

It should be noted that many parts of the Cornubian Orefield lie either on land owned by private individuals, or established bodies such as the National Trust , and Trevithick Society . Geological conservation is most important and many outcrops and mine waste dumps are either Sites of Special Scientific Interest (SSSI) or Regionally Important Geological Sites (RIGS ) and are therefore protected, hammering and collection are not permitted. Parts of the orefield in Cornwall have been designated a UNESCO World Heritage Site since July 2006 (Cornish Mining Landscape World Heritage ) and there are bids for the status of a Geopark . Membership of a society such as The Ussher Society, The Geologists' Association or Russell Society is encouraged.

The geology and mineralization topics for this site have been drawn from:

Bromley, A.V. 1989. Field Guide – the Conubian orefield. 6th International Syposium on Water-Rock Interaction, Malvern, UK.
Pattrick, R.A.D. and Polya, D.A. (eds.). 1993. Mineralization in the British Isles. Chapman and Hall.
Bristow, C.M. 1996. Cornwall’s Geology and Scenery, Cornish Hillside Publications.
Selwood, E.B., Durrance, E.M., Bristow, C.M. (eds.).1998. The Geology of Cornwall, University of Exeter Press.
Embrey, P.G. and Symes, R.F. 1987. Minerals of Cornwall and Devon. British Museum (Natural History), London.

A bibliography for the Cornubian Orefield can be downloaded by clicking here and local guides here.

Specimens of minerals and rocks shown on the is site are from the collections of the Camborne School of Mines, University of Exeter in Cornwall, Penryn, Cornwall and a tour of the CSM museum can be seen at this link, Royal Cornwall Museum, Truro, Cornwall, Royal Geological Society of Cornwall, Penzance, Cornwall, Bodmin Town Museum, Mr Courtenay Smale, Mr Bruce Grant, Mr Charles Smith, Dr Richard Scrivener and an anonymous collector.

Selected photographs have been provided by the Historic Environmental Service, Environment and Heritage, Cornwall County Council (and are the copyright of Cornwall, County Council) and Charles Winpenny (and are copyright). http://www.cornwallcam.co.uk

Certain maps and diagrams used on this site have been modified from those originally drawn by Dr N. LeBoutillier.

This site was last updated on Monday, January 15, 2007 4:39 PM .
Webmasters : Simon Camm & Paul Hedley