ORGANIC-MATTER ROLE IN ILLITIC SOIL COLLOIDS FLOCCULATION .3. SCANNING FORCE MICROSCOPY

In previous papers of this series, the flocculation of illitic colloid s separated from Hanford sandy loam diminished with the presence of or ganic matter that can form coatings on soil colloids. The purpose of t his study was to apply scanning force microscopy to image both geologi c specimen illite and the Hanford (coarse-loamy, mixed, nonacid, therm ic Typic Xerorthent) soil colloids directly to provide visual evidence of the coatings. Scanning force micrographs showed differences in par ticle morphology and surface features between the soil and the specime n illite particles that were not interpretable exclusively in terms of organic coatings but did indicate the presence of surface roughness t hat could inhibit flocculation of the soil illite particles.