Elementos traza en el cuarzo de la arena fina de Orthents de Sierra Nevada (España)

Abstract

The trace elements of the quartz mineral, in the fine sand fraction (50 - 250 μm) from two Orthent soils from Sierra Nevada have been studied. Fe3+ is the most abundant trace element, followed by Al3+, and K+, Ca2+, Na+, Mn4+, Mg2+ and Ti4+ in smaller quantities. The heteroelectric substitution in the Si4+ tetrahedra by Fe3+ and Al3+ has been evidenced, generating a deficit of positive charge which is compensated by the entrance in the crystalline network of K+, Ca2+, Na+ and Mg2+. These substitutions are more abundant in the edges of the grains than in the centres of the same ones; from what a decisive paper of the soil solution in the mobility of these elements is postulated. We propose a process of alteration of the quartz in the soil environment