The pure limestones in which karst develops have many uses:

· Building stone: easy to cut but strong and durable, limestone has been a traditional building material for many hundreds of years. The most decorative types which can take a high polish, are often described as 'marble': well-known examples are the 'black marble' of Kilkenny and the 'red marble' of Cork.

• Aggregate: crushed limestone is used for road construction, as an aggregate in concrete and cement rendering, and as loose chippings for driveways and paths.

• Agricultural lime: finely crushed and ground limestone is used to improve lime-deficient soils in many parts of Ireland. 1.1 million tonnes are spread on our fields annually.

• Cement: pure limestone is the major raw material in the manufacture of cement.

• Chemicals: many chemical processes require ground limestone or burned lime as an essential raw material, including steel manufacture.

Limestone quarry (Minerals Section, GSI)

The high demand for pure limestone has led to a thriving quarrying industry in Ireland. Currently, 21 million tonnes of limestone are quarried every year.

Quarrying has sometimes revealed very interesting karst features and has led to the discovery of some caves. However, caves and solution cavities, often filled with clay, can present quarry managers with both production and environmental problems.

Active quarrying can lead to pollution, for example from spillages of motor fuels. It is important that quarry operators take special precautions to ensure that spillages, leakages, or effluent from sanitary facilities provided for quarry workers, cannot enter the local groundwater. Unfortunately, abandoned quarries have often been used for the disposal of all kinds of waste which can also lead to pollution of groundwater as the effluents seep downwards along open fissures.

Some limestones in Ireland contain important deposits of metallic minerals (orebodies), especially lead, zinc and silver. In recent years, two large orebodies have been identified at Galmoy, Co. Kilkenny, and Lisheen, Co. Tipperary. In both cases, the orebodies lie at considerable depths below the regional water table in limestones which are at least partially karstified. In order to successfully develop these minerals it is necessary to pump out large volumes of water from the limestones. Detailed investigations of the water-bearing properties of the limestones were essential to the design of the mine and to the environmental impact assessment.