Genesis of an atypical Podzol in the Iberian Range: micromorphological characterization

Abstract

A podzol has been described in the Iberian Range (Moncayo Natural Park), which may represent the southernmost example in Europe. The fact that it occurs at the podzol distribution limit makes its morphology atypical. The aim of this work is to identify the components and formation processes of the soil, and to determine if the processes are active or paleo-processes by a micromorphological approach. The study podzol is located in the top of a northern hillside (30% of slope), at 1600 m altitude on quartzitic sandstones, under Scots pine (Pinus sylvestris) with an udic moisture regime and a frigid temperature regime. We found opaque, orthic iron oxide nodules at the base of the profile (Bhs1), which is related to a current oxidation-reduction process; silt caps are also observed on the coarse elements, pedofeatures evidencing the cryoturbation process, probably also current processes. In the Bhs2 horizon, coatings and micro-laminated clay infillings are identified that are interspersed with fine silts in the holes. Many of these coatings are fragmented and mixed with the basal mass of the soil, indicating that they are paleofeature, possibly prior to the current podzolization.