Chalk Group Lithostratigraphy: Northern Ireland - Cloghfin Sponge Beds Member

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The Cloghfin Sponge Beds Member (stratotype: near Glenarm [IGR J 971 486], up to 1.47 m thick, are restricted to the south-east Antrim region, and comprise sponge-rich, glauconitic chalk beds with cobbles at the base and 'wavy' bedding in the upper part (Fletcher, 1977). The fauna from the Cloghfin Sponge Beds includes distinctive morphotypes of the echinoid Echinocorys (Fletcher, 1977). The latter author's description of this unit appears to suggest the possibility of the Cloghfin Sponge Beds being the lateral correlative of the supposedly younger Galboly Chalk Member.

Macrofossil Biozonation: U. socialis 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.