Stratigraphic section

A vertical representation of rock layers in their stratigraphic order, showing properties such as thickness, composition, and contacts. It may be measured in an outcrop or reconstructed from subsurface data.

Connect

Stratum: A distinct layer of sedimentary or volcanic rock bounded by recognizable surfaces. A section is built from successive strata whose thickness and properties are recorded.
Measured section: A field record of a rock succession, documenting unit thicknesses, lithologies, and boundaries in sequence. This is the direct field method for producing a stratigraphic section.
Lithostratigraphy: The classification and correlation of rock bodies according to their observable lithologic characteristics. A section supplies the ordered lithologic evidence used to define and compare units.
Type section: A designated reference exposure or locality that defines the characteristic features of a stratigraphic unit. Unlike a general section, it serves as the formal reference for a named unit.
Stratigraphic contact: A boundary between adjacent rock units, reflecting deposition, erosion, intrusion, or deformation. Contacts mark where one unit ends and another begins in the vertical sequence.
Bed thickness: The distance between the lower and upper boundaries of a bed, measured perpendicular to those boundaries. Thickness records reveal changes in deposition and allow sections to be compared quantitatively.
Stratigraphic correlation: The process of matching rock units or horizons between different locations. Correlating sections reveals which layers extend across a region and where they change.
Composite section: A stratigraphic sequence assembled by joining overlapping records from multiple exposures or boreholes. It extends the record when no single outcrop or core contains the complete succession.
Lithology: The physical character of a rock, including its mineral composition, grain size, and texture. Lithology distinguishes units and helps correlate layers between exposures.
Sedimentary facies: A body of sediment or sedimentary rock with features that reflect particular depositional conditions. Facies observations give environmental meaning to the units in a section.