Resumo

PATTERER, Noelia Isabel; PASSEGGI, Esteban  e  ZUCOL, Alejandro Fabián. Phytolith analysis of soils from the southwestern Entre Rios Province (Argentina) as a tool to understand their pedological processes. Rev. mex. cienc. geol [online]. 2011, vol.28, n.1, pp.132-146. ISSN 2007-2902.

In the present contribution, the presence and distribution of siliceous microremains in characteristic soil types of the southwestern Entre Ríos Province (La Curtiembre soil series) are analyzed. The phytolith extraction was made following a methodology that comprises the physical and chemical processing of the samples. The results show that the phytolith assemblages are dominated by graminoid phytoliths, associated with arecoid ones. The graminoid types are characterized by the presence of prismatic elongated, fan-shaped and polyhedrical phytoliths among the largest components. Among the smallest phytoliths, bilobate and saddle types are abundant, especially in the samples from the upper and lower levels, whereas in the middle levels, roundel or truncated cones are more abundant. Echinate globular phytoliths are present with scarce variations across the profiles. The abundance analysis allows interpreting the presence of three phytolith sources in soil profiles. The first one is the parental material, the Tezanos Pinto Formation, principally abundant in the lower levels of the profiles. The second one originated in a past community that was present in early stages of the soils development, represented in the middle level samples of the profiles that clearly show evidence of material mobility along each profile. The third one is the phytolith assemblage of the upper levels, with a composition mainly linked to the current vegetation. The analyses demonstrated that these soils developed in a mixed community in association to a grassland dominated by panicoid and danthoniod affinities components, jointly with palms.

Palavras-chave : phytoliths; soils; Entre Ríos Province; Argentina.

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