CHARACTERIZATION OF ARCHAEOLOGICAL BLACK EARTHS IN THE MUNICIPALITY OF GURUPÁ-PA

• DOI: https://doi.org/10.22533/at.ed.973552514055

• Palavras-chave: Formation; aggregate stability; mineralogy

• Keywords: Formation; aggregate stability; mineralogy

• Abstract:

  Because of their anthropogenic origin, archaeological terra preta soils (TPA) provide information about the interactions between human populations and their environments over time. Studies aimed at clarifying these ancient settlements and the specific characteristics of the black earth soils associated with them have advanced in recent decades and have pointed to the internal variability of this type of soil. With this in mind, the aim of this study was to verify the soil attributes in areas of terra preta in different locations in the municipality of Gurupá-Pará, in order to contribute to an understanding of the formation of TPAs in this region. For this physical-chemical characterization of the soil, 8 points were collected in 8 locations with 3 depths: 10cm, 20cm and 30cm and 10 points were collected in the same locations. For aggregate stability, samples were taken at three depths. For chemical analysis, 10 soil samples were collected from each location. For mineralogical analysis, 3 TPA profiles were collected at the Gurupá-miri, Carrazedo and Gurupá sites. The DMP results show that the percentage distribution of aggregates (PDA) at a depth of 10cm was highest in the 4.76 mm class, remaining the same at the other two depths, except at site 4. Base saturation above 50% at all sites (L) attributes the Eutrophic character. Aluminum was very high and the nutrients Calcium (Ca), Phosphorus (P) and Magnesium (Mg) behaved in the same way. The predominance of kaolinite (Kt) in the three profiles analyzed was expected; goethite (gth), gibbsite (gb), strangite (str), albite (Ab), anatase (An) and tridymite (Tr) were also observed in terra preta soils, disappearing with increasing depth.