Ionic composition and distribution in saline seeps of southwestern North Dakota, U.S.A.

Soil salinization in the agricultural lands of Rhodope District, northeastern Greece

“…Richards (1974) established a linear relationship between EC and total dissolved salts, while other authors have demonstrated that a linear correlation does not always exist between the EC and the corresponding ionic species (Alvarez et al 1997;Chang et al 1983;Darab et al 1980;Rhoades et al 1989;Simon et al 1994). The formation of ionic pairs, mainly Ca 2+ , Mg 2+ , and SO 2− 4 ions (Timpson and Richardson 1986), in highly saline solutions is the main cause of this anomaly, because ion mobility in the extract is decreased (Darab et al 1980; Csillag et al 1995;Marion and Babcock 1976;Sposito 1984). Therefore, the types of soluble salt and their concentration levels directly influence the correlation model.…”

“…4) demonstrate a greater dispersion of the points and loss in linearity for ECe values greater than 5 mS/cm where the saline soil samples are separated from the alkali-saline ones due to the different increase rate of Na + and Ca 2+ . Such behavior seems to be related to the formation of ionic pairs on the part of Ca 2+ , Mg 2+ , and SO 2− 4 , which, unlike Cl − and Na + , reduce the ECe value (Timpson and Richardson 1986).…”

Evaporite Mineralogy, and Soil Solution and Groundwater Chemistry of a Saline Seep From Southern Alberta

“…Con-sequently, as saline groundwater migrates upwards to the soil surface, less soluble, evaporite minerals such as calcite and gypsum precipitate within the soil profile (Timpson et al 1986;Skarie et al 1987), whereas more soluble Na-Mg-type evaporites precipitate on the soil surface as efflorescence (Keller et al 1986a, b).…”

“…A model based on mineral precipitation was developed to predict the evaporite mineral sequence for evolution of closed-basin brines (Hardie and Eugster 1970); and has been successfully used to predict mineralogical changes in saline soils in North Dakota (Timpson et al 1986;Skarie et al 1987). …”

“…Table 1 shows the calculated K.o values at 25"C of selected evaporite minerals used in this paper. The IAP calculated using SOLMNEQ was then compared to the mineral's Kro value in Table I Alzubaidi and Webster (1983), and Timpson and Richardson (1986 For personal use only. (Fig.…”