Mining

Mining is the extraction of valuable minerals or other geological materials from the earth from an orebody, lode, vein, seam, reef or placer deposits which forms the mineralized package of economic interest to the miner.

Ores recovered by mining include metals, coal, oil shale, gemstones, limestone, dimension stone, rock salt, potash, gravel, and clay. Mining is required to obtain any material that cannot be grown through agricultural processes, or created artificially in a laboratory or factory. Mining in a wider sense includes extraction of any non-renewable resource such as petroleum, natural gas, or even water.

Mining of stones and metal has been a human activity since pre-historic times. Modern mining processes involve prospecting for ore bodies, analysis of the profit potential of a proposed mine, extraction of the desired materials, and final reclamation of the land after the mine is closed.

Mining operations usually create a negative environmental impact, both during the mining activity and after the mine has closed. Hence, most of the world's nations have passed regulations to decrease the impact. Worker safety has long been a concern as well, and modern practices have significantly improved safety in mines.

Mining (military)

Military mining, undermining or tunnel warfare is a siege method based on mining techniques which has been used since antiquity against a walled city, fortress, castle or other strongly held and fortified military position. A counter mine is a mine dug to allow defenders to attack miners, or destroy a mine threatening their fortifications.

Antiquity

The Greek historian Polybius, in his Histories, gives a graphic account of mining and counter mining at the Roman siege of Ambracia:

The Aetolians countered the Roman mine with smoke; according to Polybius, this was the first time poison gas was used.

Another extraordinary usage of siege-mining in the ancient Greece, where during Philip V of Macedon's siege of the little town of Prinassos, according to Polybius, "the ground around the town were extremely rocky and hard, making any siege-mining virtually impossible. However, Philip ordered his soldiers during the cover of night collect earth from elsewhere and throw it all down at the fake tunnel's entrance, making it look like the Macedonians were almost finished completing the tunnels. Eventually, when Philip V announced that large parts of the town-walls were undermined, the citizens surrendered without delay."

Mining (disambiguation)

Mining may refer to: