Abstract The NEXTMap Britain digital elevation model (DEM) has opened many new opportunities that considerably help and enhance the way we undertake our geological mapping of bedrock, structure, and superficial and artificial deposits. The dataset has been successfully integrated into the digital and conventional mapping workflows of the Vale of York mapping team. A variety of visualization and analysis techniques have been applied throughout the mapping process. These techniques include an initial appraisal of NEXTMap with a comparison to existing geological mapping to define the field mapping strategy and site-specific manipulation using Tablet PCs. NEXTMap interpretation has made an important contribution to the understanding of the extensive glacial and proglacial deposits found in the Vale of York; such as sand bodies resting on lake deposits, and identifying details within morainic and alluvial complexes. For bedrock mapping, NEXTMap has been used to identify landform features that relate to the underlying geology, such as breaks in slope, the extent of escarpments, hillcrests and dip slopes, to provide an overview of the landscape and to save time in mapping out features in the field. Techniques have also been developed to automatically generate these landform features. The dataset has also been used to identify areas where landsliding has occurred, for the accurate mapping of artificial ground and as a key surface for three-dimensional (3D) geological modelling.

Abstract Geomorphological, geochemical and geochronological investigations of Holocene fluvial sedimentary sequences have been undertaken within a range of upland, piedmont and lowland valley floor reaches in the Yorkshire Ouse catchment, northern England. The aims of these studies have been to: (a) evaluate the effects of prehistoric and historic land-use change on catchment erosion and sediment delivery to river channels and floodplains; (b) establish the degree to which episodes of river erosion and sedimentation are controlled by climate-related variations in flood regime; and (c) assess the spatial heterogeneity of river response to environmental change and how this is likely to influence short- and long-term sediment storage, as well as sediment transfer to the Humber Estuary. Similar discontinuities in the Holocene alluvial record are evident at many sites in the Yorkshire Ouse catchment, though local differences in river sensitivity to externally imposed change have resulted in a complicated and often unique relationship between river behaviour and environmental change. The large proportion of particulate-borne contaminant metals (resulting predominantly from historical mining) stored in the Vale of York strongly indicates that sediment delivery from the Ouse catchment to the Humber Estuary during the Holocene may have been relatively low. This suggests that the degree of connectivity between river, estuarine and coastal transport systems, as well as spatial and temporal variations in fluvial sediment storage, are the key controls of long-term land-ocean sediment fluxes.