Contemporary stromatolite formation in high intertidal rock pools, Giant's Causeway, Northern Ireland: preliminary observations.

A rare instance of contemporary stromatolite formation has been documented in the high intertidal rock pools of Giant's Causeway, Northern Ireland. These microbial structures, typically associated with extreme environments like hypersaline lagoons or Antarctic dry valleys, form here due to a combination of groundwater-fed calcium carbonate and cyanobacterial binding, while competing organisms are excluded by the pool's infrequent marine inundation and wave exposure. Two distinct stromatolite growth patterns were observed: thin, waterline-adjacent layers linked to wetting-drying cycles, and thicker, mound-like structures up to 3mm in height with internal laminae, suggesting either recent favorable environmental shifts or cyclic formation-destruction phases driven by fluctuating water chemistry.

Cooper, J. A. G., Smith, A. M., & Arnscheidt, J. (2013). Contemporary stromatolite formation in high intertidal rock pools, Giant’s Causeway, Northern Ireland: preliminary observations. Journal of Coastal Research, 165, 1675–1680. https://doi.org/10.2112/si65-283.1