Dromore Big ASSI

The quarry in Dromore Big townland is important because of its geology. In particular the quarry is the reference site for sandstones that make up the Dromore Sandstone Member, part of the Mullaghmore Sandstone Formation.

These rocks are of Carboniferous age, the geological period that lasted from 354 to 290 million years ago. During much of this period, Northern Ireland was covered by fairly shallow tropical waters.