Multidisciplinary approaches to defining historic period coastal and fluvial changes at Dunglass Burn,South East Scotland

An exceptionally thick (>2.5 m) fluvial and colluvial valley fill is described from the coastal reach of the Dunglass Burn, draining the Lammermuir Hills in south east Scotland. Buried by the valley fill is a series of charcoal accumulations interpreted as beacons to guide fishing boats, and an assemblage of large mammal bones. Radiocarbon assays on charcoal associated with these elements show them to be of early Medieval age. The onset of this extraordinary fluvial and colluvial sediment aggradation is considered to have begun at c. 1100 AD, although causation cannot be closely defined. The relations between the valley fill and securely dated built structures (buildings, bridges), an approach very infrequently explored, allow the cessation of aggradation to be dated to before the mid‐16th century AD. After c. 1600 AD incision has occurred to the present. The development of this valley fill is likely to have extensively altered the configuration of the coastline in the Medieval and early modern periods. The analyses emphasise the large magnitude of very recent landscape changes.