Silica phytoliths in Argiudolls of the Pampean plans of Argentina: biogeochemical conditions of the environment

OSTERRIETH, M.; N. BORRELLI Y D. MARTÍNEZ

Tervuren - Bélgica

Congreso; 3rd International Meeting on Phytolith Research. Man and (Palaeo) Environment: the phytolith evidence; 2000

Society for Phytolith Research

The Argiudolls of the Pampean region have evolved from wind-born sediment. Light minerals and others constituted by amorphous silica of organic origin (silica phytoliths), which reach a percentage exceeding 20%, predominate in these environs. The silica phytolith content found in cultivated and natural parcels vary according to the type of management employed: in the natural fields, maximum values are located in the superficial level; whereas in tilled soils, the maximum values are produced in the sub-superficial levels due to the plowing over of pastures. The silica phytoliths decrease grastically at the B horizons in every profile. These quantitative variations and the state of alterations that they present help to explain the high content of silica found in the underground water in the area.