Erdmann, W.; Kelletat, D., and Kuckuck, M., 2017. Boulder ridges and washover features in Galway Bay, Western Ireland.
Boulder deposits of the Aran Islands in the Galway region (western Ireland) have been under investigation for more than 10 years, whereas marine and littoral deposits inside Galway Bay have only been mentioned cursorily. The aim of this study is to investigate all coastal deposits along the most exposed bay coasts from the opening of South Sound to Black Head 25 km inside Galway Bay. Long ridges with imbricated large boulders exist near the surf belt, whereas boulder deposits in clifftop positions are mostly chaotic. The size of individual boulders is similar to those on the exposed island sites of the Aran archipelago. Landward of boulder ridges, stratified fine sediments occur that point to quiet sedimentary conditions. Two more forms and deposits are mapped that are rarely mentioned for western Europe: boulder ridges with crossway secondary ridges and tonguelike washover deposits of medium boulders, both from extraordinary flow events. Dating of all units resulted in ages back to the first half of the Holocene and mid-Holocene times. During the older periods, sea level in the area was several meters lower than today and the coastline was farther west. Dislocation of very large boulders some thousands of years ago was higher and farther inland than by the strongest storms of recent times. This requires interpretation with respect to formation processes and their results in exposed and more sheltered littoral environments.