The soil skeleton as a tool for disentangling pedogenetic history: a case study in Tuscany, central Italy

In this paper we show that the study of the soil skeleton (the > 2 mm fract ion) can be useful for detecting the presence of paleosols and events that contributed to the development of the present soil mantle. We studied profi les at four sites, all formed on sandstone in Tuscany, central Italy. The b ulk density, porosity, mineralogy, organic C, total NH4+-N and effective ca tion exchange capacity (ECEC) of the fine earth ( <2 mm) display expected t rends with depth. In contrast, data for the skeleton fraction show partiall y reversed depth trends, suggesting the occurrence of paleoevents, such as solifluction, that are considered to date from the Wurm glaciation. It is i nferred that, because the skeleton is relatively inert physically and chemi cally, it retains a memory of the pedogenetic history better than does the fine earth. The reconstruction of episodes leading to the present profiles would not have been possible from soil morphology or analyses of the fine e arth alone. (C) 2001 Elsevier Science Ltd and INQUA. All rights reserved.