Estudo hidrogeoquímico das regiões de Salobo e Pojuca, Carajás-PA

Abstract

This study aims to verify the use of the hydrogeochemical prospecting method in waters draining metasedimentary and metavolcanic rocks from the Salobo and Pojuca areas, mineralized to Cu and Cu-Zn, respectively. As a result, the chemical composition of these waters is bicarbonated, with important contributions of Mg, Na and Ca and high levels of silica, which characterize evident geochemical relationships between the aqueous medium and the geology of these regions. The pH of the waters is weakly acidic, with low concentrations of sulfate, contrary to what is observed in areas of similar mineralogy. The rainfall regime contributes to the maintenance of total dissolved solids levels, removing soluble salts accumulated in dry periods, aided by topography. The use of dissolved heavy metals to locate mineral deposits is quite limited, with large concentrations linked to stream sediments, probably iron and manganese oxyhydrate phases. However, zinc has high levels in solution, above the established background, capable of delineating important hydrogeochemical halos in the “Pojuca Area”.