Shoreline trajectories on a glacially influenced stable margin – insight from the Barents Sea Shelf, NW Russia

This study describes shoreline migration paths for late Quaternary sediments on the inner Barents Sea shelf between Kola and the Pechora Sea. The depositional geometries provide an example of stratigraphical architecture in a glacially influenced basin prone to isostatic movements as well as rapid and high-amplitude changes in eustatic sea level. The depositional geometries reflect asymmetrical relative sea level changes characterised by marine inundation upon deglaciation and prolonged forced regressions. Thus, all deposition occurs during the falling stage and lowstand systems tracts. The transgressive and highstand systems tracts are lacking and the maximum landward position of the shoreline is coinciding with the basal surface of forced regression. Shoreline migration is dominated by downward and seaward trajectories, but aggradation occurs on the falling limb of the relative sea level curve due to superimposed eustatic cycles of lower hierarchical order. Fluvial aggradation behind the shoreline takes place during the lowstand systems tract, but is also linked to high sediment supply and may also respond to superimposed lower order sea level fluctuations. Lateral variations in isostatic load due to asynchronous ice advances lead to regional variations in shoreline trajectories. Significant differences in sea level history exist across former ice margins leading to time-transgressive and laterally discontinuous stratigraphical surfaces. Sequence boundaries are not only diachronous along the depositional profile, but also laterally, and basal surfaces of forced regression are strongly diachronous across former ice margins. Absolute age control allows for estimates of the time differences along significant stratigraphical surfaces.