Category:20. N. Ireland
This account provides a broad perspective of the geology of Northern Ireland comprising the counties of Tyrone, Londonderry, Antrim, Down, Armagh and Fermanagh. The landscape of Northern Ireland is remarkably varied considering its relatively small area of about 14 000 km2 and is a reflection of the diverse geology on which it has been shaped. Figure P902264 provides a geological sketch map of this region showing the rock types occurring in relation to the major towns and cities. This account outlines the geology to a depth of at least a kilometre and summarises the current and historical use of the geological resources in the area.
Much of the surface geology of the province has been surveyed in great detail and can be examined in numerous quarries, stream and coastal exposures of rock and surface deposits. A large number of shallow boreholes, though mainly in urban areas, also provide information on the near-surface geology. Insight into the deeper geology is provided through a collection of about 45 deep boreholes, with depths greater than 200 m, drilled across the region during the last 40 years or so, in search of hydrocarbons, minerals and geothermal resources. A new geophysical survey carried out by low-flying aircraft, referred to as the ’Tellus Project’, has recently provided new high-resolution data that reveal patterns of the Earth’s gravity and magnetic field. Understanding these patterns, when combined with geophysical seismic data obtained by sending sound waves through the ground, allows interpretation of the geological structure to a depth of several kilometres.