The understanding of the processes that cause the varied distribution of silica bodies in soils is essential for the interpretation of the possible environmental factors related to their stability, sediment deposition, paleosol formation and for the analysis of archaeological sites. Thus, this study had the objective of identifying and characterizing the silica bodies morphology from surface soil horizons collected at different terrestrial ecosystems. Samples of surface horizons were collected from 10 soil profiles and heated in a muffle furnace to remove organic matter. Thereafter the samples were treated with HCl 10 % (vol/vol) to remove the soluble matter contained in each sample. The silt fraction was determined by sedimentation using particle size analysis. Most biogenic silica in soils is associated to the silt fraction. Glass microscope slide containing of this fraction were mounted on an immersion oil type A for silica body identification. The results showed a variety of forms and abundance of silica bodies in the studied soils. The variation in form and abundance was highest in the soil formed from quartzite. No differences in abundance of phytoliths were observed in the Oxisols from the Cerrado, Mata Atlântica and Caatinga biomes.
phytoliths; opal; biogenic silica; silica
