Abstract:
The Gull Island Formation is the uppermost lithostratigraphic unit of the Namurian Shannon Group and is best exposed on the Atlantic coast of southern and northern County Clare. This chapter presents excursion summaries and builds upon published observations and interpretations of the Gull Island Formation, with an emphasis on the stratigraphic architecture at several key outcrops, including those at Gull Island, Fisherstreet Bay and the Cliffs of Moher. It describes outcrops in the south and north of County Clare, where the varied nature of the Gull Island Formation can be viewed in a series of spectacular cliff sections. This review and field excursions has unearthed some lost data that has enabled refinement of the understanding of the formation. The base of the Gull Island Formation is a diachronous boundary between the coeval Ross Sandstone and Clare Shales, which was initiated in the SW and migrated north and east with time.