Fig. 5. Scanning electron micrographs of the coarse clay fraction from the Webster soil; (A) low magnification scanning electron microscopy (SEM) illustrating numerous small (0.2–2 µm) discrete particles and only a few small (1–3 µm) aggregates, (B) and (C) high magnification SEM stereo pairs illustrating platy (p), rounded (r), angular (a), and nodular (n) morphologies of the small discrete particles. Most of the surfaces of the platy and rounded particles appear smooth indicating that these particles are either uncoated or have very thin coatings of humic substances.
