Evaporite mineralogy and trace-element content of salt-affected soils in Alberta

Abstract

A survey of efflorescent crusts and associated surface soils in central and southern Alberta was conducted to determine evaporite mineralogy and elemental composition. X-ray powder diffraction indicates that efflorescence mineralogies are dominated by sodium sulfate minerals, such as thenardite and mirabilite. Sodium magnesium sulfate minerals such as konyaite and bloedite are also frequently present, with eugsterite, halite and thermonatrite among other evaporites identified. The content of selected elements in the salt crusts and surface soils was determined using instrumental neutron activation analysis. Trace-element concentrations from site to site were extremely variable. However, comparisons with elemental abundances previously reported for till and soils indicate that there is generally no mean accumulation of trace elements in salt-affected soils. Exceptions are Br and Cl, which show enrichment in soils infused with soluble salts. Key words: Salinity, trace elements, evaporites, mineralogy