The BGS Lexicon of Named Rock Units — Result Details

Larry Bane Chalk Formation

Computer Code: LBC Preferred Map Code: notEntered
Status Code: Full
Age range: Campanian Age (KC) — Campanian Age (KC)
Lithological Description: Limestone (chalk) with numerous flint bands. Shell debris abundant with distinct "pellet" or fragmentary limestone clasts evident on weathered surfaces. Three persistent erosion surfaces divide the Larry Bane Chalk Formation into two 'Beds' (A and B). These surfaces may be treated as marl seams. Very large belemnites are a prominent feature of this formation.
Definition of Lower Boundary: The lower boundary is conformable at a lower prominent erosion surface/marl (see Lithology) resting on the Boheeshane Chalk Formation.
Definition of Upper Boundary: The upper boundary is conformable and marked by an upper prominent erosion surface/marl (see Lithology) beneath the Ballintoy Chalk Formation. Overlapped by younger members at the margins of structural highs.
Thickness: 7.29m at the type-site with Bed A 2.44m and Bed B 4.85m thick. This 1:2 ratio of bed thickness is considered to be characteristic of the whole Larry Bane Chalk Formation outcrop.
Geographical Limits: Known throughout the North Antrim and east Antrim (Midland Valley) basins of Northern Ireland.
Parent Unit: Ulster White Limestone Group (UWLF)
Previous Name(s): Larry Bane Chalk (-4747)
Larry Bane Chalk Member (-4748)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Larry Bane Bay [D 058 452]. Specifically in the cliff section [D 0500 4500] 400m northnortheast of Ballintoy in the North Antrim Basin. See Fletcher (1977). 
Reference(s):
Fletcher, T P. 1967. Correlation of the Cretaceous exposures of east Antrim. Unpublished MSc Thesis, Queens University, Belfast. 
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