| dc.description.abstract | Recent progress in the understanding of the processes and products of glacial
deposition in valleys, based mainly on work in actively glaciated environments, has led to the
development of a general model of glacial valley landform-sediment relationships by Eyles
(1983). Models which predict sediments from landforms can be of considerable use to
engineers planning construction development in relict glaciated valleys, where the planning and
execution of a ground investigation survey must yield the maximum geological Information. This
study forms a critical review of the theory and practice involved in the characterisation of, and the
inter-relationships between such landforms and sediments, and proposes a new conceptual
model for their analysis, based on the case study of 7 sites In 4 British valleys glaciated during
the Dimlington Stadial.
Landforms have been characterised by mapping the surface morphology of a series of
study areas using air photos and field survey. A feature-based morphological subdivision of the
terrain was used to delineate landform associations used for further analysis. The sediment data
from the available borehole log descriptions was initially stored in the geotechnical database
GEOSHARE and was characterised in order to determine the main sediment facies present in
the study area. The identification of facies groups making up the local stratigraphy was carried
out by multivariate hypothesis testing. The plotting of the facies identified in the form of cross-sections
and the contouring of the unit surfaces has yielded information on the distribution of
sediment facies to compare with the distribution of landforms in the study areas in S Wales and
the central Highlands of Scotland.
By a process of investigation of the landform-sediment relationships of these glaciated
valleys the first steps have been taken towards the identification of some aspects of glaciated
valley sedimentary architecture, and means by which glacial terrains might be investigated using
the information stored in the landforms. In particular it is noted how the appropriate model for
landform-sediment relationships in a modern setting should be based on an analysis of
postglacially 'evolved' sedimentary sequences in the appropriate local topographic framework.
The active glacial settings used by Eyles (1983) are inappropriate as they reflect process
environments which are subsequently heavily modified by deglacial events | en_US |
