stratigraphische

Stratigraphy is the branch of geology that studies the arrangement and composition of rock layers, or strata, with emphasis on their relative ages and spatial relationships. The adjective stratigraphische is the German form used to describe stratigraphy-related topics, such as stratigraphische Einheiten or stratigraphische Korrelation.

Stratigraphic units are organized into a hierarchy, including beds, members, formations, and groups. A stratigraphic column records the vertical sequence and thickness of these units, while correlation seeks to align equivalent layers across different geographic areas despite lateral changes in lithology.

Stratigraphy relies on several subdisciplines. Lithostratigraphy classifies rocks by lithology; biostratigraphy uses fossil assemblages to define relative ages; chronostratigraphy ties rock units to actual geologic ages; magnetostratigraphy uses magnetic polarity records; sequence stratigraphy interprets layer stacking in relation to changing accommodation space and sea level.

Historically, stratigraphy developed from field observations and the work of early paleontologists; William Smith popularized faunal succession, enabling correlation by fossils. Modern practice is standardized by organizations such as the International Commission on Stratigraphy, which defines formal stratigraphic units and boundary ages, including global boundary stratotype sections and points (GSSPs).

Applications include petroleum geology, hydrogeology, paleoenvironmental reconstruction, and tectonic studies. Limitations arise from erosion, tectonic reworking, unconformities, and diachronous boundaries, which can complicate precise correlations. The term stratigraphy and its German form stratigraphische are widely used in geology education and scientific literature.