loesspaleosol

Loesspaleosol, or loess-paleosol sequence, is a geological and soil-science term that describes a vertical profile preserved within loess deposits in which cycles of loess deposition are intercalated with intervals of soil formation. During cooler and drier glacial periods, wind-blown loess accumulates. In warmer and moister interglacial phases, soils develop on the exposed loess surface, creating paleosol horizons that are later buried by new loess deposits.

Paleosols within loess sequences exhibit typical signs of pedogenesis, such as clay illuviation, soil horizon differentiation, root traces, and mottling. Some horizons may include calcareous or natric features, iron-oxide nodules, or secondary carbonate accumulations. The loess layers themselves are usually fine silt with sharp upper boundaries and can be rich in quartz and feldspar. The resulting sequences record repeated cycles of erosion, deposition, and soil formation, which can produce substantial thicknesses in favorable regions.

Dating and interpretation of loess-paleosol sequences rely on radiometric methods, including luminescence dating of loess, radiocarbon dating of organic material within paleosols, and magnetostratigraphy. Correlation with marine isotope stages and regional climate proxies aids in reconstructing past climate changes, vegetation, and dust flux associated with glacial cycles.

Distribution and significance: Loess-paleosol sequences are widespread in the Northern Hemisphere, notably on the Chinese Loess Plateau, and are also found in Central Asia, eastern Europe, and parts of North America. They are foundational for understanding Quaternary climate change, soil-forming processes in loess environments, and the dynamics of aeolian landscapes.