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.     

On the frontier of the Western Shire,British Central Africa

Superficial deposits (residual, colluvial, alluvial) are important as environmental resources in tropical environments. An understanding of their formation through varying time periods is essential to a correct interpretation of their economic and hazard potentials. This requires an integration of process studies with a reconstruction of longer term development. Saprolite formation is considered over 10⁵‐10⁷ yr, while colluvial and alluvial sediments are commonly Late Quaternary (10³‐10⁵ yr) in age. The importance of Quaternary environmental changes in the humid tropics to an understanding of heavy mineral placer deposits in West Africa and Indonesia is illustrated. It is concluded that geomorphologists can often make their most important contributions to developing areas by offering a sound interpretation of landsurfaces and their underlying deposits for engineers, geologists and pedologists, with whom a close working relationship is essential.