This paper describes laboratory testing of 148 samples collected from Southern Alberta for erosion by wash and splash. Rainfall intensity was held constant during these tests. Soil aggregation was the most significant variable explaining soil loss. The significance of other soil properties, such as organic carbon and clay content is variable, depending on the interrelationships among aggregate stability, organic content, and clay content of particular soils. Variations in erodibility of the major soils examined are explained by the resistance of aggregates to compaction and dispersion. Splash detachment and wash transport are the dominant erosion mechanisms in inter-rill areas.

Effect of soil properties on erosion by wash and splash

Further x-ray and chemical work on suspended sediment samples and cored samples from the James River and its estuary support earlier proposals by the author. A chlorite-like clay is forming from weathered illite through a mixed-layer illite—vermiculite-chlorite stage, and some illite is seemingly regenerated to a better illite by potassium fixation. Chemical analyses of interstitial water, hydrochloric acid-leachate, and fused samples offer explanations regarding the chemical changes occurring in clays as composition of the environment changes. Magnesium is adsorbed by clays to a far greater degree than potassium in the marine and brackish environment. The variance between clays found in Recent and ancient sediments is related to and explained by the concept of the equivalence level. It is suggested that K+ is adsorbed preferentially to Mg2+ by clays when they have been buried to a depth that is greater than that of the Mg2+ — K+ — equivalence level; above this level Mg2+ is preferentially adsorbed by the clays. The trifold nature of clay minerals in terms of their origin and distribution is briefly discussed.

Adjustment of Clays to Chemical Change and the Concept of the Equivalence Level

The theoretical significance of soil erodibility variations in the processes of hillslope erosion has long been recognized by geomorphologists, but few attempts at assessment have been made. A labo...

Water Erosion by Splash and Wash and the Erodibility of Albertan Soils

Swelling clays, also known as expansive clays, are encountered extensively all over the world. These clays are problematic for geotechnical engineering applications because of distress caused to structures and infrastructure as a result of swelling and swelling pressure. These clays are also often used in geoenvironmental engineering applications because of their effective barrier properties as liner materials, e.g., in landfills, ponds, and cutoff trenches. In this study, we report the effect of dielectric constant of fluid on the permeability and consolidation characteristics of Na-montmorillonite swelling clay to investigate the role of clay-fluid molecular interactions on the macroscale properties of the clay. A new “porous rigid wall, flexible wall” permeability device specifically designed for swelling clays that allows for accurate measurement of permeability, swelling pressure and consolidation characteristics, and evaluation of microstructure of swelling clays with fluids with different polaritie...

Insight into Role of Clay-Fluid Molecular Interactions on Permeability and Consolidation Behavior of Na-Montmorillonite Swelling Clay

Water-Sorption Characteristics of Clay Minerals

Homoionic samples of four montmorillonite clays, selected on the basis of the properties which control their economic uses, were prepared by treating with two normal neutral solutions of ammonium acetate, lithium, sodium, potassium, calcium, and magnesium chloride. Atterberg plastic and liquid limits, slopes of the liquid limit curves, and water sorption curves were determined. Among the results suggested, the following are particularly considered:

W. Arthur White

Papers

Water Sorption Properties of Homoionic Montmorillonite