Fig. 7. X-ray diffraction patterns of the clay fraction of the Escuro River and Fazenda River mangrove soils at depths of 0 to 20 and 60 to 80 cm; S = smectite, V = vermiculite, M = mica, K = kaolinite, Fd = feldspar, Gb = gibbsite, Q = quartz, An = anatase.