Dammskikt

Dammskikt is a Swedish term referring to a thin layer within soils or sediments that is dominated by fine mineral particles derived from airborne dust. In English-language soil and sedimentology literature, it is often described as a dust layer. Dammskikt can occur at the surface or within the upper soil horizons and is typically characterized by a fine-grained, often silt- and clay-rich composition, with relatively low organic matter compared with adjacent horizons.

Formation of dammskikt occurs through aeolian deposition of mineral dust carried by winds from distant deserts or arid regions. It can also form from volcanic ash fall or long-range transport of industrial or agricultural dust. Over time, the layer may become buried by subsequent soil development, bioturbation, or sedimentation, preserving the dust horizon within a stratigraphic sequence.

Identification relies on field and laboratory methods. Field descriptions note a distinct, uniform, fine-textured layer that contrasts with surrounding horizons. Laboratory analyses include grain-size distribution, mineralogical composition, and geochemical signatures to distinguish dust-derived material from locally produced soil components or organic layers.

Significance of dammskikt lies in its value as a marker horizon. It can provide information about past atmospheric dust flux, climate conditions, and landscape disturbance. In soils, the presence of a dammskikt can influence properties such as moisture retention, aeration, and nutrient dynamics, and it may reflect historical land use or regional environmental change.

Dammskikt occur in a range of environments, from arid and semi-arid regions to landscapes affected by episodic dust events or volcanic activity. Its interpretation often depends on regional soil classification schemes and stratigraphic context.