Aufliegende

Aufliegende is a term used in geology and stratigraphy to describe rock units that lie on top of another unit. As an adjective, it denotes the vertical position of a layer or formation in relation to underlying rocks, indicating that the overlying unit is younger than what lies beneath. The phrase is commonly applied to sedimentary, volcanic, or metamorphic sequences in field notes, maps, and cross-sections.

Contacts between aufliegende and underlying units can be conformable, where deposition continued with continuity, or unconformable, where a gap in time, erosion, or non-deposition separates the two. Determining the nature of the contact relies on field observations such as bedding, lithology, fossils, and sedimentary structures, and may be corroborated by absolute dating when available. The concept aligns with the principle of superposition, which states that younger rocks overlie older rocks in a sequence.

In practice, the overlying material may be described as aufliegende Schicht or aufgelagerte Schicht, with synonyms such as überliegende Schicht used in less formal contexts. The term is widely used in geological mapping, paleogeographic reconstructions, and structural geology to convey the relative age and depositional history of rock units.

Etymology: aufliegen means to lie on, with aufliegend forming the participle used to describe the overlying rocks. See also unterliegende Schicht (underlying), Überlagerung (overlying relationship), and Konformität/Unkonformität (conformity/unconformity).