New age-estimate data and implications for marine isotope stage 7 and 5e sea levels in Fenland, eastern England

Only one last interglacial relative sea-level indicator point (SLIP) has been recognised for Fenland, eastern England, and the nearest penultimate interglacial SLIP is located on the north Norfolk coast. Such limited information restricts the regional input to, and hence the relevance of, global reconstructions of late Middle and Late Pleistocene sea level. Marine-influenced deposits without such relevant data are known in Fenland, but their age and connection to past relative sea level (RSL) were largely uncertain. To improve this situation, new age-estimate data are presented and assessed in combination with existing age-estimate and new and existing palaeoecological data. Sea level relative to the marine-influenced deposits of Fenland is approximated based on brackish-marine faunal analyses. Results distinguish between marine-influenced deposits of penultimate and last interglacial sites. Fenland marine-influenced deposits of both interglacial stages share similar altitudinal envelopes (between a few metres above and below present ordnance datum (OD)), in common with Kirmington to the north and those of the British south coast, the Channel Islands and northwest France. Peak Fenland minimum RSL approximation (RSLA) of 2.5 m OD in the penultimate interglacial is commensurate with the north Norfolk coast SLIP but contrasts with the below OD peak of the global record. Timing of the peak Fenland maximum RSLA of 3.75 m OD late in the last interglacial at 116 ± 16 ka is commensurate with the Dutch record (116–105 ka), but contrasts with the early peak of some global records.