Coastal lagoons and beach ridges as complementary sedimentary archives for the reconstruction of Holocene relative sea-level changes

Coastal lagoons and beach ridges are genetically independent, though non-continuous, sedimentary archives. We here combine the results from two recently published studies in order to produce an 8000-year-long record of Holocene relative sea-level changes on the island of SamsO, southern Kattegat, Denmark. The reconstruction of the initial mid-Holocene sea-level rise is based on the sedimentary infill from topography-confined coastal lagoons (Sander etal., Boreas, 2015b). Sea-level index points over the mid- to late Holocene period of sea-level stability and fall are retrieved from the internal structures of a wide beach-ridge system (Hede etal., The Holocene, 2015). Data from sediment coring, georadar and absolute dating are thus combined in an inter-disciplinary approach that is highly reproducible in micro-tidal environments characterised by high sediment supply. We show here that the commonly proximate occurrence of coastal lagoons and beach ridges allows us to produce seamless time series of relative sea-level changes from field sites in SW Scandinavia and in similar coastal environments.