Mining  Mining Techniques  Quarrying

Quarry

A quarry is a kind of open-pit mine from which rock or minerals are extracted. Quarries are normally utilized for extracting building materials, like dimension stone. Quarries are normally shallower than other kinds of open-pit mines. Quarries are also at times used as filming locations.

In other words a quarry is a big man-made hole in the ground from where minerals or rock are taken out. Quarries are made when big deposits of commercially helpful minerals or rock are found close to the Earth's surface. Quarrying is a type of mining and is also called as open pit mining or strip mining. When minerals are found profound beneath the surface, a deep mine has to be dug to dig out them. Quarries are normally dug deeper and bigger; awaiting the mineral resource is worn out. When they are no longer used, quarries are frequently utilized as landfill sites for the disposal of waste.

Problems

Quarries in level areas frequently have particular engineering problems for drainage. The Coquina Quarry is excavated to more than 60 feet (18 m) beneath sea level. To lessen surface leakage, a moat lined with clay was constructed round the complete quarry. Ground water that leaks into the pit is pumped up into the moat.

Many quarries fill with water after desertion and turn into lakes. Further quarries are made into landfills.

Kinds of rock

Kinds of rock extracted from quarries comprise:

• Cinder
• Chalk
• China Clay
• Clay
• Coal
• Coquina
• Construction aggregate (sand and gravel)
• Globigerina Limestone (Malta)
• Granite
• Gritstone
• Gypsum
• Limestone
• Marble
• Ores
• Phosphate rock
• Sandstone
• Slate