NATURE OF CEMENTING MATERIALS IN ORTSTEIN HORIZONS OF SELECTED FLORIDA SPODOSOLS .1. CONSTITUENTS OF CEMENTING MATERIALS

Five pairs of ortstein and nonortstein spodic horizons of Haplaquods were studied in an attempt to identify the nature of cementing materials. The ortstein horizons had significantly larger amounts of dithionite-citrate-extractable Al, significantly higher silt plus clay contents, and significantly higher bulk density values than did nonortstein spodic horizons. Moist and air dried ortstein samples had similar shear strengths, but the strength significantly decreased by correlation with the dithionite-citrate-extractable Al. Energy-dispersive spectra showed that Si and Al were major constituents of both ortstein and nonortstein samples. Ortstein samples had stronger Al peaks, however. More cementing materials were observed in the ortstein than nonortstein samples in scanning electron micrographs. Additional study results are discussed.