type section
Defining rock layer
A type section is the specific sequence of rock strata at a particular location that serves as the definitive reference for a stratigraphic unit.
Geologists designate type sections to establish standards for identifying and correlating rock formations across different regions.
When a new geological formation is formally described, the type section provides the benchmark against which other occurrences are compared.
The type section for the Morrison Formation is located in Colorado.
- referenceDirecting attention elsewhere
- reference pointStandard for comparison
- boundaryLine marking a limit
- geologyStudy of Earth's composition
- stratigraphyStudy of rock layers
geologic time scale · outcrop · formation · bedrock · layer · horizon · specimen · locality · fossil · sediment · limestone · shale · epoch · stage · Jurassic · biozone · correlation · golden spike
- stratastratum, strata, bed, layer, layers
- biostratigraphyzonation, faunal succession
- Early Jurassicichthyosaurs, ammonites, Dilophosaurus, marine fossils, early mammals