SOIL MAGNETISM AS A FUNCTION OF SLOPE, NORWESCOR HOLSTEIN FARMS IN STARK CO., OHIO

This study investigated the role of surface slope on the enhancement of the magnetic properties of the A/B soil horizons compared to the underlying C horizon. Pedogenic magnetic enhancement is the result of weathering parent material to produce ferrihydrite and then dehydration and oxidization to form magnetite and maghemite. In temperate climates, magnetically enhanced soils are best developed on well-drained, level surfaces. This study examined three soil profiles from a flat hilltop, steep hillslope and a flat hill bottom located on Norwescor Holstein Farms in Stark Co., Ohio. Subsamples were collected from each soil profile and measured for magnetic concentration, grain size, and mineralogy parameters. The A and B soil horizons contained greater ferrimagnetic concentration compared to the subsoil. The magnetic grain size was finer grained and there was more magnetite concentration at the top of the soil profiles compared to the subsoil. The expected increase in peodogenic superparamagnetic (SPM) magnetite was found in the A/B horizon of the hilltop and hill-slope soil pits. However, the flat hill bottom site does not show pedogenic enhancement of SPM ferrimagnetic magnetite possibly because of reductive diagenesis due to gleying.