The BGS Lexicon of Named Rock Units — Result Details

Ballycastle Chalk Formation

Computer Code: BCCK Preferred Map Code: notEntered
Status Code: Full
Age range: Maastrichtian Age (KM) — Maastrichtian Age (KM)
Lithological Description: Limestone (chalk) with nodular flint bands that have a carious habit in the upper part of the formation. Divided into seven "Beds" (A to G).
Definition of Lower Boundary: The lower boundary is conformable on the Port Calliagh Chalk Formation at a prominent weathered-out bedding plane at the top of "Bed" F of that lower formation and characterized by tabulate flints.
Definition of Upper Boundary: The upper boundary is at the erosional contact with Palaeogene Basalts or Quaternary deposits.
Thickness: 13.72m at the type-site.
Geographical Limits: Northern Ireland. Limited to the Ballymagarry and Ballycastle areas by the effects of pre-Palaeogene erosion. Ballymagarry Quarry, Castle Point Quarry and cliffs and foreshore eastward to Ballycastle.
Parent Unit: Ulster White Limestone Group (UWLF)
Previous Name(s): Ballycastle Chalk Member [Obsolete Name and Code: Use BCCK] (-4444)
Ballycastle White Limestone (upper part) [Obsolete Name and Code: Use BCCK] (-2582)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  West of Ballycastle Pier. Full formation visible in cliffs and wave-cut platform to the west of the pier. 
Reference(s):
Fletcher, T P. 1967. Correlation of the Cretaceous exposures of east Antrim. Unpublished MSc Thesis, Queens University, Belfast. 
Wood, C J. 1967. Some new observations on the Maastrichtian Stage in the British Isles. Bulletin of the Geological Survey of Great Britain, Vol.27, 271-288. 
Fletcher, T P. 1977. Lithostratigraphy of the Chalk (Ulster White Limestone Formation) in Northern Ireland. Report of the Institute of Geological Sciences, No. 77/24. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable