The Khulsan locality, which is the stratotype of the Barun Goyot Formation, Mongolia

A stratotype or type section in geology is the physical location or outcrop of a particular reference exposure of a stratigraphic sequence or stratigraphic boundary. If the stratigraphic unit is layered, it is called a stratotype, whereas the standard of reference for unlayered rocks is the type locality.[1]

Also it can be defined as "The particular sequence of strata chosen as standard of reference of a layered stratigraphic unit."[This quote needs a citation]

When a stratigraphic unit is nowhere fully exposed, the original type section may be supplemented with reference sections covering the full thickness of the unit. A reference section may also be defined when the original type section is poorly exposed, or for historical units which were designated without specifying a type section according to more modern standards.[2]

See also


  1. ^ "Stratotypes and Type Localities". International Commission on Stratigraphy. Retrieved 20 August 2017.
  2. ^ North American Commission on Stratigraphic Nomenclature (November 2005). "North American Stratigraphic Code" (PDF). AAPG Bulletin. 89 (11): 1563. Bibcode:2005BAAPG..89.1547.. doi:10.1306/07050504129. Retrieved 8 August 2020.