Chalk mining

Chalk mining is the extraction of chalk from underground and above ground deposits by mining. Mined chalk is mostly used to make cement and bricks. Chalk mining was widespread in Britain in the 19th century, due to the large amount of construction underway (and the Industrial Revolution). Some chalk mines were extensively large, with passages up to 25 feet (7.6 m) high and 15 feet (4.6 m) wide, their passages taking the form of an Norman arch. Because of chalk's softness, picks and shovels were used to excavate tunnels. Stepped slabs were dug into the chalk, allowing many miners to dig at the same time. Care had to be taken to avoid collapse and areas where the chalk was soft were simply abandoned.

A link was recently discovered between sinkholes opening up in the UK and the location of former chalk mines. Due to the softness of chalk, rain and erosion has caused the ground in some places to collapse into the remnants of ancient chalk mines and tunnels.

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