Four soils of the Ultisol order in the St. Francois Mountains of Missouri, which were developed in loess and rhyolite residuum, were characterized to: (i) describe the dominant soil series and landscape characteristics having mass-wasting features, (ii) identify the types of parent materials, and (iii) evaluate the soil profile descriptions and associated geochemical data to estimate the influence of eluviation-illuviation processes on soil profile expression. In particular, we wished to document the interhorizon transport of an array of elements associated with eluviation-illuviation processes and its importance to understanding soil genesis. The presence of argillic horizons and nutrient accumulations in the near-surface horizons infers stable landscapes. Aqua regia digestion Fe concentrations of the four pooled pedons show a positive and linear relationship with clay content, suggesting that the parent materials and their weathering histories are similar across the sampled pedons. Iron, Al, Cu, Zn, K, Ni, Cr, Ga, Sr, Sc, As, Li, Rb, V, P, S, Sn, Cs, Th, and U are preferentially partitioned in the clay fraction. For the pooled pedons, elemental ratios of V, Sc, Ni, As, Cr, Cu, Cs, Li, Rb, Th and U with respect to Fe are presented as evidence that the parent materials are similar and that loess weathering greatly contributes to the fine earth fraction.
1Department of Geoscience, Southeast Missouri State University, One University Plaza M 6100, Geoscience Dept., Cape Girardeau, MO 63701. Dr. Aide is corresponding author. E-mail: firstname.lastname@example.org
2Department of Agriculture, Southeast Missouri State University, Cape Girardeau, MO.
Received May 11, 2008, and in revised form December 19, 2008.
Accepted for publication January 12, 2009.