Iron and Calcium Biomineralizations in the Pampean Coastal Plains, Argentina: Their Role in the Environmental Reconstruction of the Holocene

Abstract

Biomineralizations are biogenic composites, crystalline or amorphous, produced by the metabolic activity of organisms distributed all over the world. The aim of this work was to evaluate the presence of iron and calcium biomineralizations and their influence in the physicochemical and mineralochemical variations in paleo and actual pedosedimentary sequences of the coastal plains in Mar Chiquita. The complex interaction of calcium with iron biomineralizations, as framboidal and poliframboidal pyrites associated with gypsum, barite, calcite, halite, and iron oxyhydroxides, have demonstrated the active and complex biogeochemistry that occurs in the temperate-wet paleoesturaries and estuaries of the coastal Pampean Plains. Particularly the consequences that different human activities could have, such as the possible acidification processes as result of the iron sulfide oxidation.