Soils and Paleosols

Authors

Daniel R. Muhs, U.S. Geological SurveyFollow

Date of this Version

2021

Citation

Muhs Daniel R. (2021) Soils and Paleosols. In: Alderton, David; Elias, Scott A. (eds.) Encyclopedia of Geology, 2nd edition. vol. 5, pp. 370-384. United Kingdom: Academic Press. dx.doi.org/10.1016/B978-0-12-409548-9.12002-0

Comments

U.S. government work

Abstract

This article reviews the nature of modern and ancient soils. Soils are naturally occurring bodies that mantle most of the land surface of the Earth. They are found on virtually every part of the Earth’s land surface, other than areas covered by water bodies (lakes and rivers), glacial ice, or steep slopes in mountainous terrain. Soils occur at the interface of the geosphere, hydrosphere, biosphere, and atmosphere and are the medium of growth for much of the Earth’s plant and animal life. The study of soils as naturally occurring bodies on the Earth’s surface is called pedology (in contrast to edaphology, which is the study of soils and their relations with plants, particularly crops). Soil geography is a function of the combined effects of climate and vegetation, as well as parent material composition, parent material age, and topography (Jenny, 1941, 1980; Birkeland, 1999; Buol et al., 2003; Bockheim, 2014; Schaetzl and Thompson, 2015). Because of their close links to climate, vegetation, and age of parent material, soil analysis is a powerful tool in Quaternary stratigraphy, geomorphology and landscape evolution, and paleoclimatology. Ancient or “fossil” soils are called paleosols. Paleosols are soils of the past, often buried by younger sediments, and are particularly important in stratigraphy, interpreting past conditions of climate or vegetation, and the duration of land surface stability. Although much study has been made of paleosols within the Quaternary, there is an increasing recognition that there are paleosols in the pre-Quaternary rock record as well, and such features often give important clues about past climates and vegetation. Before such interpretations can be made, however, it is necessary to understand the nature of modern soils and the environmental conditions under which they form.