What is stratigraphy in geology?

Stratigraphy is a branch of geology that studies rock layers and how they form, primarily focusing on sedimentary and layered volcanic rocks. It uses subfields like lithostratigraphy, biostratigraphy, and chronostratigraphy, alongside core principles such as the law of superposition and cross-cutting relationships, to decipher Earth history. This field provides the foundation for the geologic time scale and standardizes global chronostratigraphic units.

What we know

• Stratigraphy is a branch of geology concerned with the study of rock layers and layering processes, primarily applied to sedimentary and layered volcanic rocks. [1, 2]
• Stratigraphy features three related subfields: lithostratigraphy, biostratigraphy, and chronostratigraphy. [2]
• The field relies on several foundational principles and laws, including the principle of original horizontality, the law of superposition, cross-cutting relationships, inclusions, and faunal succession. [2]
• The International Commission on Stratigraphy is responsible for defining global chronostratigraphic units used to divide geological time. [3]

Where to go next

• how it workedWhat are the core laws of stratigraphy?
• what followedHow does the geologic time scale work?
• a case in pointWhat is a geological formation?
• how we knowWho oversees global chronostratigraphy?
• compared withHow does stratigraphy compare to geochronology?
• an unexpected connectionHow did Abraham Gottlob Werner shape modern geology?The foundational concept of a geological formation goes back to Abraham Gottlob Werner's theory of the origin of the Earth developed between 1774 and 1817.

Sources

• [1]stratigraphy (Wikidata Q134783) · CC0 1.0
• [2]Stratigraphy · CC BY-SA 4.0
• [3]Geologic time scale · CC BY-SA 4.0
• [4]Geological formation · CC BY-SA 4.0
• [5]International Commission on Stratigraphy · CC BY-SA 4.0