Global Boundary Stratotype Section and Point (GSSP)

This is an internationally agreed-upon reference point on a stratigraphic boundary section that defines the boundary between two stratigraphic units of global standard stratigraphic ages. After detailed investigations of related global stratigraphic sections, the typical section, stratigraphic sequence, and reference point are officially announced, and once a GSSP boundary has been agreed upon, a permanent marker is driven into the geologic section to mark the precise boundary; this marker is known as a ‘golden spike’. The GSSPs are defined according to the rules compiled by the International Commission on Stratigraphy (ICS), and the verification process is conducted by respective branch working groups of the ICS in an organized manner. After being selected by the branches, the proposed GSSPs are then submitted to the ICS for voting, and the agreed-upon GSSPs are passed to the International Union of Geological Sciences (IUGS) for formal approval. The selection of GSSPs is a scientific...