Classification of paleosols

Despite increased interest in paleosols during the past decade, no satisfactory classification is in current use. Presented here is a largely descriptive classification system that utilizes those pedogenic features that have the highest preservation potential in the rock record. Emphasized in the classification are morphological and mineralogical features that are easily recognizable in the field and through the petrographic microscope.

The classification is based on evaluation of the relative prominence in a paleosol of six pedogenic features or processes: organic matter content, horizonation, redox conditions, in situ mineral alteration, illuviation of insoluble minerals/compounds, and accumulation of soluble minerals. The most prominent of these six features/processes provides the key to classifying a paleosol into one of nine orders. Four of the order names are borrowed from Soil Taxonomy (Histosol, Spodosol, Oxisol, Vertisol), whereas the other five order names are presented here for the first time (Calcisol, Gypsisol, Gleysol, Argillisol, Protosol). The orders may be preceded by one or more subordinate modifiers that describe other important features of the paleosol. The classification is relatively easy to apply to the rock record and should enhance communication and aid in the standardization of terminology