A rare discovery of a pristine 200-year-old cobalt mine has been made in Alderley Edge in Cheshire, North West England. The National Trust has issued a press release giving details of the find, which was first made by Derbyshire Caving Club. The mine has been described as a ‘time capsule’, offering a rare glimpse into the miners’ day to day work.
The National Trust developed an immersive fly through to record 3D visual details of the complex underground tunnel network, which extends 10 meters beneath the earth. Several artefacts and items of mining equipment have also been recovered from the mine, including a clay bowl, pipes, leather shoes, and buttons from clothing.
Cobalt is a ‘transition metal’, meaning that it is found in the mid-point of the Periodic Table. In its purest form, it is a silvery blue colour, which has led to it being used for decorative purposes in ancient Eastern cultures. Samples of cobalt colourings in glass and pottery objects have been found in King Tutankhamen’s tomb in Egypt, according to Live Science.
Cobalt mining didn’t begin in earnest until the 17th century, and even then it was a difficult process, as it is only found in small deposits in the earth’s crust. The name cobalt translates to ‘goblin’ in German; apparently a reference to the toxic gases that cobalt mining can release. Cobalt is used today for its magnetic properties.
The chemical element also has radioactive isotopes, which are used in some forms of gamma ray cancer treatment. It is mainly imported to England, but when these ceased during the Napoleonic Wars (1803-1815), the Alderley Edge mine and others were brought into operation.
However, when imports resumed after the wars, many cobalt mines in England closed, including the Alderley Edge mine. Ed Coghlan of the Derbyshire Caving Club said: “In the time the Club has been active here, we have explored a number of disused historic mines and made some significant discoveries.”
He added: “But many mines have been filled in with rubble over the years or with sand washed into them by heavy rainfalls or they have been accessible in some form since they were abandoned, so anything of interest had been removed.”
“To find a mine in pristine condition, together with such personal objects and inscriptions, is rare. It is a compelling window into the past and to the last day when the mine workers stopped their activities.”
A detailed 3D scan has been made of the mine, which will allow researchers to digitally explore the interior and contents, even though general access will not be maintained.
Jamie Lund, an archaeologist with the trust, explained: “This mine hasn’t been disturbed by later mining, it’s not been broken into by kids in the 1960s, it’s not been filled with bottles or other rubbish. It literally is a time capsule in terms of giving a glimpse into the environment that these miners, who were extracting cobalt, encountered.”
“We quickly agreed that the real significance of this site is the fact that it has that pristine nature of an environment that the miners might have left yesterday. As a result, it will shortly be sealed again with the artefacts inside, the oxygen allowed to run out “and the policy will be to stay out”.
There is a rich history of mining in Alderley Edge, which is an escarpment clearly visible against the surrounding flat Cheshire landscape. Since the Bronze Age, the area has been mined for lead and copper.
There are already many ex-mining tunnels which are now owned by the National Trust. The last mines closed during the 1920s, and from the 1940s to the 1960s, much of the tunnel network was left open for free visitor access. However, after a series of accidents, the tunnels were closed off, and now only supervised groups are allowed.
The area is also noted for being a rich source of finds for gold artefacts. A gold bar weighing 97.01 grams was found in the early 1990s, which was declared to be 73% pure gold, and others have been discovered since. A Roman coin hoard of 564 coins dating rom AD 317-36 was found in 1995 by Derbyshire Caving Club.
The area is also popular with tourists who drawn by the association with the legends of the Wizard Merlin and the sleeping White Knights, which inspired Alan Garner’s acclaimed 1960 novel The Weirdstone of Brisingamen.
If you are looking for plant hire in Chiswick, please talk to us today.