A long-term natural experiment in pedogenesis

Abstract

In assessing the effects of a particular factor in soil formation, field situations are sought in which most of the variables are comparable except the factor chosen for study. In many cases this is difficult. The effects of climate, for example, may not be easy to tease apart from those of vegetation. For the study of the role of particular factors in the formation of paleosols, it is also important to select examples where other factors of the paleoenvironment and diagenetic alteration were comparable. This may seem a daunting exercise, but it is in principle no different from interpretative paleoecology or sedimentology. There are many questions of general scientific interest concerning conditions of soil formation that only can be addressed using paleosols. In the geologically distant past, for example, climatic conditions were not always linked with the same kind of vegetation as that of today. The fossil record of soils can be considered a long-term natural experiment in which many of the factors of soil formation operated in fundamentally different combinations.