Barbiéro Laurent auteur aut IRD Rezende A. auteur aut IRD Furquim S.A.C. auteur aut IRD Furian S. auteur aut IRD Sakamoto A.Y. auteur aut IRD Valles V. auteur aut IRD Graham R.C. auteur aut IRD Fort M. auteur aut IRD Ferreira R.P.D. auteur aut IRD Neto J.P.Q. auteur aut IRD text journalArticle eng text/pdf born digital access Joint pedological, geochemical, hydrological and geophysical investigations were performed to study the coexistence or saline and freshwater lakes in close proximity and similar climatic conditions in the Nhecolandia region, Pantanal wetlands in Brazil. The saline lakes are concentrically surrounded by green sandy loam horizons, which cause differential hydrological regimes. Mg-calcite, K-silicates, and amorphous silica precipitate in the soil cover, whereas Mg-silicates and more soluble Na-carbonates are concentrated in the topsoil along the shore of the saline lake. In saline solutions, some minor elements (As, Se) reach values above the water quality recommendations, whereas others are controlled and incorporated in solid phases (Ba, Sr). Locally, the destruction of the sandy loam horizons generates very acidic soil solution (pH similar to 3.5) through a process not yet understood. The soil distributions indicate that some freshwater lakes are former saline lakes. They are invaded by freshwater after destruction of the sandy loam green horizons, then the freshwater becomes enriched in K+, SO42-, Fe, Al, and a stream of minor and trace elements. The formation of these green sandy loam horizons in the saline environment and their destruction in the non-saline one emphasizes the dynamic nature of this environment (C) 2008 Elsevier B.V. All rights reserved. specialized Alkalinity Sodicity Saline lake Soil hydrology Nhecolandia Pantanal Brazil BRESIL 068 062 064 148 1 91-106 2008 0016-7061 https://www.documentation.ird.fr/hor/fdi:010044155 10.1016/j.geoderma.2008.09.010 0016-7061 [F B010044155] https://www.documentation.ird.fr/hor/fdi:010044155 https://www.documentation.ird.fr/intranet/publi/2009/01/010044155.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2009-02-06 2017-08-23 fdi:010044155 fre