Concentration diagrams based on Na contents showing the regional trends (solid line) compiled from Furian et al. [32] and the chemistry of waters collected in auger holes along the transect of Salina Verde.

<p>Note the sigmoidal shape of dissolved K along the concentration process.</p

X-ray diffraction of glycoled-oriented clay along the transect showing smectite-dominant (1) and mica-dominant horizon (4).

<p>X-ray diffraction of glycoled-oriented clay along the transect showing smectite-dominant (1) and mica-dominant horizon (4).</p

Near infrared reflectance on fine clay material of horizon 1 and 4.

<p>V and δ denote stretching and bending, respectively.</p

Standard soil layout and clay fraction distribution compiled from previous studies carried out around saline-alkaline lakes in Nhecolândia.

<p>See text for description of horizons 1 to 4.</p

Mossbauer spectroscopy carried out on fine clay material of the greenish horizon 4 dominated by Fe-mica.

<p>The deconvolution into 3 doublets shows octahedral Fe³⁺ (doublets 1 and 3) and secondarily octahedral Fe²⁺ (doublet 2).</p

Location of the studied transect at the border of Salina Verde in the Pantanal wetland of Nhecolândia.

<p>Location of the studied transect at the border of Salina Verde in the Pantanal wetland of Nhecolândia.</p

Examples of alkaline lakes in the Nhecolândia showing elongated deep borders (arrows) suggesting that the chemical withdrawal-aggradation process impacts the lake depression.

<p>Bar = 200 m. Original pictures are available at Google Earth^TM imagery.</p

Cross section showing the soil layout along the transect.

<p>AH are auger holes for water collection, Electrical conductivity (EC) in mS cm^-1, ⊗ are samples presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0159972#pone.0159972.g005" target="_blank">Fig 5</a>, Pz denotes the piezometer used for water level monitoring in the beach.</p

Water level monitoring of the fresh watertable of the draining fields, the saline beach groundwater and Salina Verde.

<p>Level zero corresponds to the bottom of the lake.</p

Mössbauer spectrometry characteristics of fine clay mica from horizon 4.

<p>Mössbauer spectrometry characteristics of fine clay mica from horizon 4.</p