Drummahon ASSI

Drummahon is a special place because of its earth science interest. The occurrence of rocks known as conglomerates at this locality is unique within the Skea Sandstone Member.

This site is of geological importance because it is the only known occurrence of coarse conglomerates within the Skea Sandstone Member of which it forms a part.

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.

The rocks in this area are exposed along a steep slope. The most common rock found here are conglomerates. These rocks are formed from material, including large clasts, eroded from other rocks. The material contained in them tells geologists something about what rocks were exposed at that time.