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  2. List of Global Boundary Stratotype Sections and Points

    en.wikipedia.org/wiki/List_of_Global_Boundary...

    This is a list of Global Boundary Stratotype Sections and Points. Since 1977, Global Boundary Stratotype Sections and Points (abbreviated GSSPs) are internationally agreed upon reference points on stratigraphic sections of rock which define the lower boundaries of stages on the geologic time scale .

  3. Global Boundary Stratotype Section and Point - Wikipedia

    en.wikipedia.org/wiki/Global_Boundary_Stratotype...

    A Global Boundary Stratotype Section and Point (GSSP), sometimes referred to as a golden spike, is an internationally agreed upon reference point on a stratigraphic section which defines the lower boundary of a stage on the geologic time scale.

  4. Stage (stratigraphy) - Wikipedia

    en.wikipedia.org/wiki/Stage_(stratigraphy)

    For younger stages, a Global Boundary Stratotype Section and Point (GSSP), a physical outcrop clearly demonstrates the boundary. For older stages, a Global Standard Stratigraphic Age (GSSA) is an absolute date. The benchmarks will give a much greater certainty that results can be compared with confidence in the date determinations, and such ...

  5. Terreneuvian - Wikipedia

    en.wikipedia.org/wiki/Terreneuvian

    Its top is defined as the first appearance of trilobites in the stratigraphic record around 521 million years ago. [4] This series' name was formally accepted by the International Commission on Stratigraphy in 2007. [2] The Fortunian stage and presently unnamed Cambrian Stage 2 are the stages within this series.

  6. Stratotype - Wikipedia

    en.wikipedia.org/wiki/Stratotype

    In geology, a stratotype or type section 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 ...

  7. Kimmeridgian - Wikipedia

    en.wikipedia.org/wiki/Kimmeridgian

    The Global Boundary Stratotype Section and Point (GSSP) for the base of the Kimmeridgian is the Flodigarry section at Staffin Bay on the Isle of Skye, Scotland, [7] which was ratified in 2021. The boundary is defined by the first appearance of ammonites marking the boreal Bauhini Zone and the subboreal Baylei Zone. [ 8 ]

  8. Cambrian - Wikipedia

    en.wikipedia.org/wiki/Cambrian

    For global stratigraphic correlation, the ICS ratify rock units based on a Global Boundary Stratotype Section and Point (GSSP) from a single formation (a stratotype) identifying the lower boundary of the unit. Currently the boundaries of the Cambrian System, three series and six stages are defined by global stratotype sections and points. [1]

  9. Global Standard Stratigraphic Age - Wikipedia

    en.wikipedia.org/wiki/Global_Standard...

    In the stratigraphy sub-discipline of geology, a Global Standard Stratigraphic Age, abbreviated GSSA, is a chronological reference point and criterion in the geologic record used to define the boundaries (an internationally sanctioned benchmark point) between different geological periods, epochs or ages on the overall geologic time scale in a chronostratigraphically useful rock layer.