EVALUATING THE GENESIS OF "MAUMEE II" SHORELINE NEAR WAUSEON, OHIO, USA

Winameg and Lyle's ridges, previously mapped as the Lake Maumee II shoreline in northwest Ohio, were studied using light detection and ranging images (LiDAR), electrical resistivity, ground penetrating radar (GPR), ground-truthing pits and auger sampling to better understand the geological history and timing of events of Late Wisconsinan deglaciation in the region. Recently available LiDAR data shows the ridges in greater detail than previous studies. These ridges present a distinct morphology (i.e. discontinuous, thicker and higher relief) that is not characteristic of nearby strandlines such as the Whittlesey shoreline immediately to the south, suggesting a more complex history. Spit forms and escarpments are present, as is a ~0.5 km wide channel parallel to the ridges on the basinward side. These ridges are steep on the west (hummocky terrain) and stand up to 7 meters above the adjacent till and glaciolacustrine plain to the east. Auger sampling revealed 6 meters of sand overlying clayey silt at Winameg ridge and more than 3 meters of fine, pebbly sand above silt at Lyle’s ridge. Sediments at both ridges coarsen upwards. The GPR and resistivity profiles penetrated 4-8 meters and up to 18 meters in depth, respectively. Our lithologic interpretations are based on hand-dug pits and auger samples. GPR data at both ridges show horizontal sand bedding. The hummocky and pitted nature of the landscape adjacent to these ridges, and the observation that sand and gravel thickness is less than the relief of the ridges suggest discontinuous ridge formation from localized, moraine sediment along an ice margin.