StratumStufen

StratumStufen is a descriptive term in stratigraphy used to denote a pattern of discrete, step-like transitions within a sedimentary succession. The term combines Stratum, meaning layer, and Stufen, meaning steps, and refers to intervals where properties of successive layers shift abruptly enough to create a rung-like progression within an otherwise continuous sequence.

Formation and meaning: StratumStufen arise in sequences where depositional regimes change on relatively short timescales, such as cyclic climate forcing, sea-level fluctuations, or pulses of sediment supply. The steps are marked by abrupt changes in grain size, sorting, composition, bedding style, or fossil content between adjacent layers, while the overall stratification remains recognizable.

Interpretation and use: The concept helps interpret paleoenvironmental dynamics and aids correlation between stratigraphic sections. StratumStufen are not formal lithostratigraphic units; they describe within-sequence features that may indicate discrete depositional episodes or climatic pulses and can be employed in sequence stratigraphy to identify cycles.

Observations and criteria: Researchers identify StratumStufen by abrupt changes in measurable properties such as color, grain size, sorting, mineralogy, fossil assemblages, or geochemical markers across thin boundaries. Validation typically requires multiple lines of evidence, including textural analyses and, when available, chemostratigraphic data.

Limitations and scope: The clarity of StratumStufen depends on preservation, diagenesis, and subsequent deformation. They are most evident in high-resolution records from deltaic, fluvial, or shallow-marine environments with cyclic deposition.

See also: Stratigraphy, Cyclic sedimentation, Parasequence, Sequence stratigraphy, Lithostratigraphy.

References: In geological literature, StratumStufen appears as a descriptive pattern within discussions of cyclic sedimentation and stratigraphic correlations in German- and English-language sources.