Clogher Valley Fault is a geological fault in

County Fermanagh County Fermanagh ( ; ) is one of the thirty-two counties of Ireland, one of the nine counties of Ulster and one of six counties of Northern Ireland. The county covers an area of and had a population of 63,585 as of 2021. Enniskillen is the ...

Northern Ireland Northern Ireland ( ; ) is a Countries of the United Kingdom, part of the United Kingdom in the north-east of the island of Ireland. It has been #Descriptions, variously described as a country, province or region. Northern Ireland shares Repub ...

. The focus of deformation during the Variscan Orogenic Cycle in Northern Ireland was located on, and between, two major faults. In the north is the northern-bounding fault of the Midland Valley

Terrane In geology, a terrane (; in full, a tectonostratigraphic terrane) is a crust fragment formed on a tectonic plate (or broken off from it) and accreted or " sutured" to crust lying on another plate. The crustal block or fragment preserves its d ...

, the Castle Archdale Fault-Omagh Thrust Fault zone, while in the south is the Clogher Valley Fault. Carboniferous rocks located between these faults were affected by

strike-slip In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

, associated with intermittent dextral

transpression In geology, transpression is a type of Strike-slip fault, strike-slip deformation that deviates from simple shear because of a simultaneous component of shortening perpendicular to the fault plane. This movement ends up resulting in oblique shear. ...

and

transtension Transtension is the state in which a rock mass or area of the Earth's crust (geology), crust experiences both ''extensive'' and ''transtensive'' Shear (geology), shear. As such, transtensional regions are characterised by both extensional structures ...

. Between the Clogher Valley Fault and the Southern Upland Fault, the southern bounding fault of the Midland Valley Terrane, the Carboniferous rocks are relatively undeformed.

References

* Map sheet 44 (and accompanying memoir) of the series of 1:50,000 scale geological maps of Northern Ireland published by Geological Survey of Northern Ireland. * Lyle, P. 2003 Classic geology in Europe 5 ''The north of Ireland'' Terra Publishing, Harpenden Seismic faults of Northern Ireland Geography of County Fermanagh {{Fermanagh-geo-stub

See also

References