Fig. 2. X-ray diffraction (XRD) patterns of Okeechobee mud sediment clay (Mg-saturated, glycerol solvated) and silt from specified stations and depths. Minerals indicated are sepiolite (Se), palygorskite (Pa), quartz (Qz), aragonite (Ar), calcite (Ca), and dolomite (Do). The peaks without a mark are from the XRD slide mount. Smectite was also present in most Okeechobee mud samples (including O7, above), but smectite XRD peaks were only marginally evident before K saturation (not shown) (Whittig and Allardice, 1986).