Chalk Group Lithostratigraphy: Northern Ireland - Larry Bane Chalk Member

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The Larry Bane Member (stratotype: Larry Bane Bay [D 055 447]), c. 7.29 m thick at its type locality is principally distinguished by the fact that it is delineated by two conspicuous erosion surfaces at its top and base, with a further erosion surface dividing the unit in two, about a third of the way up (Fletcher, 1977). The fact that the member was divided up by the erosion surfaces in a thickness ratio of 1:2, was regarded as a crucial point in its recognition (Fletcher, 1977), but is perhaps insufficient justification for this otherwise undistinguished flinty chalk unit being accorded Member status. Fletcher (1977) and Wilson & Manning (1978) designated the two units of the Larry Bane Member 'A' and 'B' in ascending stratigraphical order. Overall, the fauna of the Larry Bane Member is characterised by the brachiopods Cretirhynchia woodwardi and Kingena pentangulata, large examples of the belemnite Belemnitella, and the echinoid Echinocorys ex gr. conica (Wilson & Manning, 1978).

Macrofossil Biozonation: B. mucronata Zone (pars)

Correlation: see Correlation with other UK Chalk Group successions

References[edit]

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.

WILSON, H E & MANNING, P I. Geology of the Causeway Coast, Vol. 2. Memoir of the British Geological Survey of Northern Ireland.