Mountfield Quarry ASSI

Mountfield Quarry exposes a section through the Omagh Thrust Fault, a major structural feature in Northern Ireland’s geology. The site is important as it allows study of the structural relationship between the youngest rocks of the deformed Dalradian sequence and the Tyrone Volcanic Group.

Mountfield Quarry offers unique access to the plane of the Omagh Thrust, one of the most important structural discontinuities in Northern Ireland. It is of international geological importance since it provides evidence of the nature of late-Caledonian to Variscan modification of the boundary between the Central Highlands (Grampian) Terrane and the Midland Valley Terrane.