3D MODELING OF QUATERNARY GRAVEL AQUIFERS: INTEGRATING OUTCROPS, CORES, GEOPHYSICS AND GOCAD
(1) Glaciolacustrine gravel-delta (local-scale): the meso-scale distribution of gravel- and sand-beds within delta-foresets were analysed for the water-saturated aquifer using data from nearby outcrop-analogs, from borehole cores and from geophysical measurements. Based on the sedimentological model the aim of further studies is to develop hydrogeological models which can be validated by hydrogeological field measurements on the test site.
(2) Transition from terminal moraine complex to proglacial sandur (kilometer-scale): based on facies associations recognised in spot outcrops and a larger number of well data the large-scale dynamics of glacier advance and retreat was reconstructed for the study area. The sedimentary architecture is characterised by the interfinging of glaciofluvial gravel and diamict deposits of different origins. A 3D visualisation in GOCAD depicts the complex subsurface stratigraphy, which determines the hydrostratigraphy and the distribution of aquifers and aquicludes in the area.
In conclusion it is apparent that interpreting all available geological and geophysical data leads to more realistic reconstructions of aquifer heterogeneity than purely stochastic approaches.