The vault beneath the UK's largest salt mine where thousands of earth cores from prehistoric London are stored
This article originally appeared on Culture24.
35 million years of London's geology is preserved 150 metres underground in a Cheshire salt mine
DeepStore's mine, in Cheshire, used to only be accessible via 150 metre deep shafts. Nowadays the shafts are wider and contain lifts© Courtesy CrossrailBeneath the UK’s largest salt mine, DeepStore in Winsford is a natural, climate-controlled storage facility and the home of thousands of soil and rock cores from beneath London.
Victorian salt miners© Courtesy CrossrailThe cores include London Clay, sands and clays of the Lambeth Group, Thanet Sands and Chalk. They tell the story of how geological activity has shaped the earth on which London sits, covering a time span of about 35 million years. The oldest Crossrail core is 80 million years old.
The salt was removed by conveyor to hopper lifts in one of the shafts. The mining operation was largely automated and could be run by four people© Courtesy CrossrailOnce removed from the ground, the soil and rock cores lose moisture and slowly deteriorate. The cores at DeepStore are contained 150 metres underground at a consistent humidity level and an ambient temperature of 15 degrees Celsius.
Room and Pillar mining at DeepStore © Courtesy CrossrailThe conditions prevent deterioration without the use of a temperature controlled warehouse.
A geological fault core© Courtesy CrossrailIn 1992, before construction began in 2009, comprehensive ground investigations showed that these soil and rock cores were extracted from more than 1,400 boreholes – at depths of up to 70 metres.
© Courtesy CrossrailThe cavernous Cheshire space was created when millions of tonnes of salt were excavated from Compass Minerals UK's rock salt mine. DeepStore is now home to 1.8 million square metres of storage space – more than 700 football pitches in size.
© Courtesy Crossrail‘Room and Pillar’ mining at DeepStore produces a rectilinear arrangement of ‘pillars’ and ‘rooms’. Approximately one third of the salt is left in ‘pillars’ to support the roof of the mine.
The Crossrail room at the mine© Courtesy CrossrailThe mine is currently a network of rooms and pillars that covers an area of three miles by five miles. There are many decades of reserves. DeepStore build walls around empty ‘rooms’ in the mine to create storage areas. Typically these are full of racking, storing documents in boxes.
© Courtesy CrossrailThis brightly coloured Lambeth Group core, taken from Tottenham Court Road, shows a mangrove swamp was here 55 million years ago.
© Courtesy CrossrailThis is a chalk core sample from Woolwich station. The material is 85 million years old.
© Courtesy CrossrailThis is a London Clay core from Paddington.
What do you think? Leave a comment below.Three museums to explore geology and mining inBig Pit: National Coal Museum, BlaenafonBig Pit is a real colliery. Kitted out in helmet, cap-lamp and battery pack, you descend 90 metres
to another world; a world of shafts, coal faces and levels, of
underground roadways, air doors and stables.
Killhope The North of England Lead Mining Museum, County DurhamKillhope was one of the most productive lead mines in England during the late 1800s. Current exhibition Life as a Miner features a video on geology, a miner's kitchen, a manager's drawing room and a two metre tall fantastical display of minerals assembled into a miniature cavern. Until November 1 2015.
Purbeck Mineral and Mining Museum, DorsetPartly formed to enhance the visitor experience when visiting the Swanage Railway, this museum is built on redundant clay workings adjacent to the Norden park and ride and Station, and features a typical ball clay drift and Norden No 7 mine Transhipment buildin.
Source: http://www.culture24.org.uk/history-and-heritage/art535084-giant-vault-beneath-salt-mine-where-thousands-earth-cores-prehistoric-london-stored
