Sammelschicht

Sammelschicht is a term used in geology and sedimentology to describe a discrete layer within a sedimentary sequence that acts as a preferential collector for material, fluids, or dissolved constituents. Such a layer can form when depositional conditions change in a way that promotes accumulation, such as a decrease in energy that allows finer particles to settle, or through chemical or biological processes that concentrate substances at a particular horizon.

Formation and characteristics: Sammelschichten may consist of clay-rich laminas, organic-rich intervals, or mineralogical zones where minerals precipitate from pore waters and cement the sediment. They often reflect a specific depositional environment or diagenetic event and can display distinctive lithology, mineralogy, or geochemical signatures that make them useful as stratigraphic markers.

Role in stratigraphy and geology: In stratigraphic work, Sammelschichten can aid in correlating units across a basin by providing a recognizable horizon tied to a particular set of depositional conditions. They may influence the porosity and permeability of the host rock, acting as seals, aquitards, or as zones that modify fluid flow and reservoir behavior. In some contexts, Sammelschichten may host mineral or hydrocarbon concentrations due to their accumulating properties or chemical conditions.

Terminology and usage: The term is primarily found in German-language literature. In English-language contexts, related concepts might be described as accumulation horizons, collecting layers, or trap layers, depending on the specific genesis and the geological setting.

Overall, Sammelschicht denotes a horizon within rocks characterized by its tendency to collect or concentrate materials, providing both practical and interpretive value in sedimentary geology.