Soil Science · 1982 · 44 citations · 0 references
Natural SciencesEarth SciencesSoil SciencesGeochemistrySedimentologySoil ScienceIron OxidesSediment ChemistrySediment CompositionSoil CompositionSoil GeochemistrySoil HorizonsB HorizonsEnergy Dispersive X-ray SpectroscopyEnergy-dispersive X-ray SpectroscopyMetal Speciation In SoilSediment GeochemistrySedimentary Iron GeochemistrySedimentary Organic Matter CompositionSpodic Horizons
Centrifugation for long times or at high speeds resulted in progressively decreasing concentrations of iron and aluminum in 0.1 M sodium pyrophosphate extracts of soil. Centrifugation at 80 000 g for 6 hours, as compared with 20 000 g for 20 minutes, decreased the Fe concentrations from 23 to 80 percent and the Al concentrations from 9 to 35 percent in nine samples of podzolic B horizons. The sediments contained Fe, Al, Si, P, and Na, as indicated by energy dispersive x-ray analysis, and carbon. Chemical analysis of some of the sediments showed that Fe was usually the dominant component, but that percentages of Al and Fe were similar in extracts of two Fe-poor B horizons. The results are discussed in relation to the concept that 0.1 M sodium pyrophosphate extracts organic complexes of Al and Fe, and in relation to chemical criteria for spodic horizons.