The BGS Lexicon of Named Rock Units — Result Details

Cushendall Formation

Computer Code: CDAL Preferred Map Code: DALL
Status Code: Full
Age range: Early Devonian Epoch (DL) — Early Devonian Epoch (DL)
Lithological Description: Conglomerate, grey to greyish purple, dominantly of weathered rhyolite and basalt clasts, sandstone, volcaniclastic, very coarse-grained and pebbly to medium-grained, thin reddish brown mudstones.
Definition of Lower Boundary: Abrupt transition from preceeding Ballyagan Formation by appearance of conglomerates and increase in volcaniclastic detritus.
Definition of Upper Boundary: Probable faulted contact with Cushendall Porphyry although it has been suggested there is evidence of a flow-foot breccia and that the porphyry is thus extrusive.
Thickness: 0-200m (0-656ft).
Geographical Limits: Northeast County Antrim between Cushendun and Cushendall on the southeast flank of Cross Slieve.
Parent Unit: Cross Slieve Group (CSSL)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Reference Section  Shoreface cliffs and outcrops on the southeast side of Cross Slieve extending south from Port Obe to Salmon Rock at the north side of Cushendall Bay. Irish Grid 
Simon, J B. 1984. Provenance and depositional history of the Lower Old Red Sandstone of northeast Antrim. Irish Journal of Earth Sciences 6, 213-228. 
1:50K maps on which the lithostratigraphical unit is found, and map code used: