Paleosol classification: Problems and solutions

Paleosols are soils that formed on landscapes of the geologic past. Three kinds exist — buried, exhumed, and relict. To help reconstruct paleoenvironments and for ease of comparison, we suggest a property-based classification system linked to genetic processes. We use enduring properties because alteration of paleosols following burial is common. Morphological properties such as horizonation, soil fabric, root and worm casts, and redoximorphic features are resistant to alteration and thus are valuable as criteria. Field-observable and micromorphological properties, degree of weathering, and proportion of resistant minerals are also useful as criteria for paleosol orders. Total chemical analysis provides a proxy measure for base saturation and clay mineralogy. We use proxy criteria to help classify paleosols that have changed markedly or have been lithified during or after burial. To an earlier version of the system, we add two new orders and include buried, relict, lithified, and exhumed units at the suborder level. Our system clearly separates paleosol taxon names from those of all ground soils. We use the prescript paleo- at the order level, and kryptic to designate the buried, enduric to designate the relict, lithic to designate the lithified, and emergent to designate the exhumed paleosol suborders. We use prescript modifiers to describe the physical characteristics of the paleosols and postscripts for parent material origin and the extensiveness of the paleosol landscape. We present data and classify a number of paleosols as examples of the system.