A multi-proxy investigation of human–environment interactions from a coastal marsh in south-west England, UK

This research provides a rare insight into Holocene coastal environmental changes for the south-west peninsula of England. Multi-proxy paleoenvironmental analyses, including pollen, non-pollen palynomorphs (NPPs), foraminifera, microcharcoal, and geochemical analysis, were carried out on an 825 cm sediment core from a coastal marsh in Cornwall, UK. The ca. 5900-year record, supported by four radiocarbon dates, shows changes in vegetation and human–environment interactions against a background of dynamic sea level and hydrological changes. RSL was shown to be at −8.87 ± 0.16 mOD at 5905–5730 (limiting data point) and at −6.86 ± 0.13 mOD at 4342–4090 cal BP. The steady decline in arboreal species from the late Neolithic/Early Bronze Age indicates the long-term utilization of the saltmarsh for grazing. Geochemical analyses reveal that anthropogenic impacts intensified from ca. 2100 cal BP onwards, potentially in association with Late Iron Age and early Roman settlement in the St. Austell region. Collectively, the data illustrate the impact of human activities in a coastal environment, revealing significant changes to the sedimentation of the marsh in the last ca. 2100 years, including an increase in clay-sized sediments and the presence of mica particles that can be attributed to nearby china clay extraction.