cryoturbated

Cryoturbated describes soils and sediments that have been disturbed and mixed by cryoturbation, a set of processes driven by freeze-thaw cycles in cold climates. Cryoturbation is common in periglacial environments where near-surface ice formation and repeated expansion and contraction of water in soil cause mixing, heaving, and redistribution of material. The result is a disturbed vertical arrangement of horizons, sometimes with organic-rich material found at depth and mineral material from deeper horizons moved toward the surface.

The processes responsible include frost churning, frost heave, and ice segregation within the active layer above permafrost. Repeated freezing and thawing can overturn and blur horizon boundaries, create cross-cut or angled laminations, and produce mixed textures within a single pedon. Cryoturbated soils often exhibit an irregular or chaotic stratigraphy, including pockets or lenses of materials that do not align with the typical vertical sequence. In some landscapes, ice-wedge formation and other periglacial features accompany cryoturbation, further disrupting soil structure.

Cryoturbation is a common feature in periglacial and high-latitude soils, such as gelisols and related cryosols, and it can extend its influence into nearby boreal or alpine regions. The presence of cryoturbation affects soil properties including drainage, texture distribution, and organic matter placement, with implications for carbon storage, nutrient cycling, and land-use planning. Recognizing cryoturbated horizons is important for soil mapping, geotechnical assessments, and understanding past and present periglacial processes.