Lockergesteine

Lockergesteine, in geology, are unconsolidated rocks and sediments that have not undergone lithification into solid rock. They form the loose materials that overlie bedrock and cover large areas of the Earth's crust. The category encompasses a broad range of substances, including sands, gravels, silts, and clays; loess and other wind-blown deposits; alluvial and marine sediments; glacial deposits such as till and outwash; peat and other organic-rich sediments; and volcanic tephra that has not cemented.

Because they are not cemented, lockergesteine typically exhibit higher porosity and variable permeability, influencing groundwater storage and flow. Their mechanical strength is generally low and depends on moisture content, compaction, and grain size distribution, making them sensitive to loading, erosion, frost action, or liquefaction. The thickness and composition of these materials affect engineering projects, foundation stability, and slope behavior. They also host soils and ecosystems and play a key role in soil formation and nutrient cycling.

Geologically, lockergesteine form through deposition and accumulation by rivers, winds, glaciers, and biological processes, or through weathering products that accumulate as regolith. Regions shaped by glacial, fluviatile, or aeolian processes often contain substantial sequences of unconsolidated sediments. In German-speaking geology, the term is used to distinguish these surficial, unconsolidated materials from solid bedrock (Festgestein or Felsgestein).