Davinroy, Thomas C U. of Colorado, Boulder The doctoral dissertation research will examine biogeochemical and hydrologic controls on solutes and flowpaths in alpine watersheds by extending field investigations to include high-elevation talus fields. The research design integrates previous approaches and incorporates innovative isotopic research with spatially distributed hydrologic models to fully evaluate the hydrologic and biogeochemical processes which occur within alpine talus. The hydrologic characteristics of talus, including flowpaths, residence time and transmissivity will be quantified through physical measurement of natural isoptopic content and experimental addition of salt tracers. Intensive sampling of subtalus flow by vacuum evacuation techniques provides evidence of both spatial and temporal transformations of talus groundwater chemistry. Microbial processes and resultant contribution to surface water will be explored by sampling of subtalus fines to determine if they act as surrogate soils in transforming snowmelt chemistry.
