Assessment of Gully Erosion Characteristics and Soil Depth Effect on Clay Mineralogy in Coastal Plain Sands, Akwa Ibom State, Nigeria

A study was conducted in nine gully sites in coastal plain sands Akwa Ibom State, Nigeria. The gullies were group into three broad categories and at three gully slope positions, with a control site. Soil samples were collected with a spade at 0–20 cm and 20–50 cm depths. Data generated were analysed using the analysis of variance. Results revealed that clay minerals on gully categories shows there was no significant effect on the content of minerals. Assessment of clay minerals on gully slope position shows that hematite, magnetite, quartz, K-feldspar, calcite, dolomite, K20, gibbsite had significant difference among gully slope positions. Clay minerals on soil depth indicated that topsoil content of quartz (39.80 gkg-1) and K20 (1.09 gkg-1) were significantly higher than the 29.55 and 0.64 gkg-1, respectively, obtained in the topsoil.