Evaporite mineralogy and groundwater chemistry associated with saline soils in eastern North Dakota
1987
Skarie, R.L. | Richardson, J.L. | McCarthy, G.J. | Maianu, A.
Soil salinization has resulted from seepage of water from drainage ditches in eastern North Dakota. The present study was undertaken to determine the effect of these processes on the geochemistry of shallow groundwater and on the evaporite mineralogy of the affected soils. In the chloridic system studied, SO4(-2) concentrations of groundwater and saturation extracts were controlled by the solubility of gypsum. Calcium concentrations were controlled by gypsum solubility in the sulfatic system. Shallow groundwater samples collected near the recharge sources were undersaturated with respect to gypsum and oversaturated with respect to calcite. Considerable redistribution of gypsum was observed in soil profiles of strongly salinized transects of the chloridic system. Sulfate enrichment relative to Ca2+ was observed in groundwater and soil extracts collected near drainage ditches of chloridic sites. Mineralogy of efflorescent crusts included gypsum, epsomite, hexahydrite, thenardite, and konyaite in the sulfatic system, and halite, eugsterite, thenardite, konyaite, bloedite, and gypsum in the chloridic system.
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