Fig. 3. X-ray diffraction patterns of (a) the Escuro River (RE) silt fraction (60–80 cm) on oriented aggregates at room temperature, heated to 550°C, and solvated in ethylene glycol, and (b) the clay fraction, after concentration of Fe, from Pai Matos Island (PM) and Caranguejo Island (IGUA) mangrove soils at depths of 0 to 20 and 60 to 80 cm; V = vermiculite, M = mica, K = kaolinite, Q = quartz, Gt = goethite, An = anatase.