AS THE GRAINS MOVE DOWN THE CREEK: THE IPFW CASE

As water moves downstream, it carries sediments that become sorted and rounded. The purpose of this research project, a requirement for an upper level geology course, is to determine the water content of soil, overall composition of sediments (gravel, sand, etc.), and grain size changes (if it does change) along a river profile, using a creek that runs through the Indiana University-Purdue University Fort Wayne (IPFW) campus. In the 2014 Fall semester, grain size distribution analysis was performed on 14 soil samples collected along the length of the creek. Fourteen soil samples were also collected from same sites in the 2015 Spring and Fall semesters resulting in three sets of data. Collected data indicates water content and grain size distribution vary along the creek profile. Water content for the Fall 2014 samples has a range of ~20 -28%. This is closely mimicked with the Fall 2015 samples with a range 20-25%. However the Spring 2015 data begins ~28% and falls to ~24% over the course of the creek profile. This could be due to a higher influx of water during the spring season keeping the sediments waterlogged. Certain soil samples contained significantly lower water content than others, that, when examined more closely, revealed different soil profiles containing less silt-clays and higher sand-gravel. The soil composition data ranges from coarse to fine grained sands, silts, and clays with less gravel present in the recent samples. This could be due to heavy flooding experienced in this area as well as recent construction on campus. Knowing the cause(s) of finning sediments downstream in the creek may help in managing the stream and probably other rivers in northern Indiana. This is an ongoing research and new data will be presented.