Reflectance spectra of synorogenic sediments accumulating in a modern foreland basin indicate that alluvial-fan sediment changes composition as drainage networks expand through tilted strata. The spectral signatures of several sediment mixtures can he used to identify zones of lithologic mixing and to infer erosional unroofing sequences and drainage development in a modern foreland region.
A practical graphic analysis of sediment mixing was developed for digital Landsat thematic mapper data. This technique determines the relative proportions of end-member compositions in a binary sediment mixture. Vegetation effects on the spectral response of rock and sediment can also be evaluated.