Assinaturas geoquímicas dos perfis de solo do sítio arqueológico do município Bom Jesus do Tocantins – Pará

Abstract

The integration of morphological, mineralogical and chemical data of a soil with Archeological Black Earth (ABE) and surrounding Argissolos allowed to indentify the main process acting on the ABE formation from Bom Jesus do Tocantins, southeast Pará State. The similarity between these data in the subsurface horizon of ABE and surrounding soils indicate that ABE was probably developed from Argissolos with subsequent pedogenetic transformation through the input of organic and inorganic materials (kitchenware, foods and other materials of animal and vegetable origin) by ancient human settlements that promoted the thickness of the surface horizon and higher concentrations of CaO, P2O5, Zn, available P and Zn, and exchangeable Ca and Mg in relation to surrounding Argissolos. Furthermore, this anthropic influence also resulted in changes of subsurface horizon of Argissolos with ABE, such as high concentrations of P2O5 and available P. The Soil Taxonomy and Brazilian System of Soil Classification (BSSC) are suitable to identify ABE, since they prioritize in the soil orders the main pedogenetic process acting on soil formation and development, related to the subsurface horizon, and subsequent pedogenetic transformations in the surface horizon. Moreover, this study propose the addition of diagnostic properties such as ceramic and lithic artifacts, P2O5 and available P and Zn, organic carbon, Ca2++ Mg2+, CEC and base saturation index in the surface horizon of Soil Taxonomy and BSSC to group and differentiate several types of anthropic soils of Amazon region.