Summary of site:
To place this site in context, the Slieve Gullion Ring – Overview, site 1118, should be read.
Reynolds, researching this area in the 1940s and early 50s, described 13 layers of rock forming the central pile of Slieve Gullion and this quarry exposes layers 7, 8 and 9. He regarded them as lava flows but they are now considered to be horizontal intrusions of molten magmas into the host rock of the area, the Newry granodiorite. Before weathering seriously compromised the faces it was possible to see detached blocks of Newry granodiorite suspended in the layers and in the process of conversion into microgranites. Cavities in the rocks were lined with the needle-like crystals of the green mineral, actinolite, a calcium silicate with iron and magnesium, a member of the amphibole family. There are fresh exposures on the roadside near the quarry and more further up the road.
This is one of a suite of key sites which together record the essential history of the Slieve Gullion Ring complex. The quarry faces now need to be refreshed to show the interrelationship between these intrusions and their hybrid rocks.