Mineralogical study of salt efflorescences on soils of the Jequetepeque Valley, northern Peru☆

Abstract The mineralogical composition and fabric of salt efflorescences from five localities in the Jequetepeque Valley, northern Peru, were studied. Most information is derived from the study of thin sections, supplemented by chemical data, XRD analyses and SEM observations. Three mineral assemblages are distinguished: halite-trona-thenardite, halite-trona-thenardite-burkeite-pirssonite and halite-thenardite-eugsterite. The habit of the various mineral species and the relations among different components are described for each crust and some tentative explanations are offered for certain features that were observed. It is concluded that thin sections can be a powerful tool for the interpretation of the information and diagenesis of salt minerals in soil efflorescences.