The rocks are coarse-grained deposits of Cementstone and Fell Sandstone age. The succession in the Rerrick outlier consists of the Wall Hill sandstones (900 ft.) unconformable on Silurian, followed by the Orroland Limestone Beds (80ft. +) yielding fossils indicative of Cambeck age. The succeeding coarse red Barlocco conglomerate (210 ft. +) is capped by the Rascarrel beds, some 1,200 ft. of felspathic sandstones and arkoses, with coarse conglomerates. The rocks of the three outliers to the east are of Barlocco-Rascarrel facies. All four outliers are downfaulted against Silurian and have a regional dip to the south-east.