THE IMPACT OF AGRICULTURAL PRACTICES ON SEDIMENT SUPPLY TO THREE SMALL LAKE BASINS IN NORTHEAST OHIO BASED ON THE RECORD OF SEDIMENT CORES FROM NORTHEAST OHIO

Sediment cores extracted from three lake basins in Northeast Ohio reveal a marked transition from organic rich late Holocene muds to sediments richer in clastics in two of the basins, while the third and smallest lake basin contained no such transition. Analyses of sediment cores from Long Lake were conducted at the LacCore facilities in Minneapolis, Minnesota and revealed an increase in magnetic susceptibility and gamma density measurements, which are consistent with an influx of eroded soils into the aquatic system. Radiocarbon dating of material gathered from the noted transition dates to the early 19^th century. The drainage basins range in size from Odell Lake, which is 52 km² to Long Lake, at 6 km² to Round Lake, which has a drainage area of less than 1 km². The transition in sediment type is easily detected in the cores extracted from Odell Lake and Long Lake but not in the cores retrieved from Round Lake. The difference in sedimentation is likely due to the varying drainage basin sizes of the three lakes and varying land use histories influencing the fluvial input of eroded materials. Five meters of sediment overlay the transition in Odell Lake and three meters overlay the Long Lake transition. At the time of the transition, which dates to the early 19^th century, European settlers were moving into Northeastern Ohio and beginning to clear land for farming. Small lake basins that were not in agricultural areas do not contain a visible transition, whereas larger basins received tens of centimeters to meters of sediment over the past 200 years. In more recent times, land use changes, such as railway construction, an amusement park on the banks of Odell Lake, and septic systems leaking into the drainage basins may also account for some of the increase in sediment deposition. Ongoing chemical analysis of sediment cores extracted from the three lake basins is being conducted in order to determine the sediment supply contributed from modern agricultural and land use changes.