Summary of site:
Unit 5 of this Devonian sequence is the topmost; for a general account of all units see Key Site 1148 ‘Devonian-Red Arch Formation; Cushendall to Red Arch, Glenariff’.
Unit 5 is the only unit not completely exposed on the coast, so this stream section in an abandoned chalk quarry is invaluable. The unit consists of very pale sandstones at the base, white to fawn with thin beds of red-brown mudstone. Above them, 3-4m of red-brown finely laminated mudstone abruptly appears with fine, green laminations throughout. Green mudstones often contain fossil plant spores, which can be important for dating purposes, but none was found in these rocks.