EVIDENCE FROM SITES IN WESTERN IRELAND OF LATE HOLOCENE CHANGES IN COASTAL ENVIRONMENTS

The presence of sand layers interleaved with biogenic material in coastal sedimentary sequences from back-barrier areas has often been used as evidence of storm surge or tsunami action during the Holocene. This paper discusses such stratigraphies from two adjacent sites in Western Ireland in order to assess the validity of this inference. Detailed examination of the sand layers indicates that while some of the sand beds at one of the sites were deposited by overwash, other processes, including aeolian deposition and fluvial reworking of aeolian sediments were also important in sand redistribution in the back-barrier areas. In these cases, local controls, including site drainage characteristics, barrier morphology and available sediment supply, appear to have been important in site evolution. A regional signal of storm frequency was not detected.