Sedimentology and Geochemistry of the St Joseph River, Allen County
Dr. Aranzazu Pinan-Llamas
Former Department of Geosciences
Department of Manufacturing & Construction Engineering Technology
The St. Joseph River Watershed is one of eight watersheds that make up the Maumee Watershed. This river was originally carved by the Huron-Erie Glacial Lobe approximately 22,000 years ago. Formation of this watershed ended approximately 12,000 years ago with the final retreat of the Erie Lobe. Over time, anthropogenic activity has altered the watershed by draining wetlands and turning the land into farm and cropland. Prior studies found that pesticides, pollutants, and nutrient loading were the main concerns in water quality, and that erosion and flooding were the largest overall concerns. Our study aims to analyze the St. Joseph River along four transects ranging from southeast DeKalb County to Allen County. Coarsest sediments were found near the center of the channel, while sediments fined toward the inner part of meanders. Longitudinally, the highest abundance of coarse grains was found toward the northernmost sample site (upstream). Based on our data, the grain size distribution depends on the geometry of the channel. Geochemical analyses of the water during a time span of five months (October-February) show a general decrease in the concentration of NO3, PO4, and SO4, and a slight increase in the concentration of Fe2+ and Cl2. In the same months, while pH and dissolved oxygen readings were stable, total dissolved solids showed a general decrease.
Summers, Harlie; Niswonger, Kenneth; Aby, Tessay; and Deifenbaugh, Dan, "Sedimentology and Geochemistry of the St Joseph River, Allen County" (2017). 2017 IPFW Student Research and Creative Endeavor Symposium. 4.