SUBSURFACE STRATIGRAPHY AND AQUEOUS GEOCHEMISTRY AS INDICATORS OF HYDROLOGY IN BEACH-RIDGE COMPLEXES: TWO CASE STUDIES FROM THE UPPER GREAT LAKES
We have used an integrated approach of water sampling for aqueous chemical indicators and groundwater flow modeling to study Negwegon State Park in Alpena, MI and Lake Superior State Forest in St.Vitals Bay, MI. Samples from surface water and groundwater wells installed into the upper aquifer were analyzed for field parameters and major ions (specific conductance, temperature, pH, Eh, and alkalinity). Samples were distributed along transects originating at the Lake Huron beach and extending 1500 and 800 meters inland, respectively.
Preliminary results from work at St. Vitals Bay and Negwegon State Park suggest that we can identify end members of the hydrologic continuum at each site using water chemistry indicators. Furthermore, the distribution of flow systems is influenced by the presence or absence of low conductivity zones (clay layers) that are indicated by data collected from ground penetrating radar, vibracores, continuously recorded pressure transducers, and aqueous geochemistry.