Information about Global Boundary Stratotype Section And Point

A Global Boundary Stratotype Section and Point, abbreviated GSSP, is an internationally agreed upon stratigraphic section which serves as the reference section for a particular boundary on the geologic time scale. The effort to define GSSPs is conducted by the International Commission on Stratigraphy, a part of the International Union of Geological Sciences. Most, but not all, GSSPs are based on paleontological changes. Hence GSSPs are usually described in terms of transitions between different faunal stages, though far more faunal stages have been described than GSSPs. The GSSP definition effort commenced in 1977. As of 2004, 45 of the 96 GSSPs required have been approved.

An ideal GSSP would

• be accessible by public transit from a major airport
• be accessible to research
• be extensive enough to ensure future access
• be easily related to other exposures worldwide
• contain a radiometrically datable bed at the boundary, and
• include well defined markers at the stage boundary that can be applied worldwide.

No GSSP is ideal.

Agreed-upon GSSPs

Main article: List of Global Boundary Stratotype Sections and Points

The Precambrian-Cambrian boundary GSSP at Fortune Head, Newfoundland is a typical GSSP. It is accessible by paved road and is set aside as a nature preserve. A continuous section is available from beds that are clearly Precambrian into beds that are clearly Cambrian. The boundary is set at the first appearance of a complex trace fossil Trichophycus pedum that is found worldwide. The Fortune Head GSSP is unlikely to be washed away or built over. Trichophycus pedum is less than ideal as a marker fossil as it is not found in every Cambrian sequence, and it is not assured that it is found at the same level in every exposure. Further, it has since been identified in strata 4m below the GSSP!^[1] However, no other fossil is known that would be preferable. There is no radiometrically datable bed at the boundary at Fortune Head, but there is one slightly above the boundary in similar beds nearby. These factors have lead some geologists to suggest that this GSSP is in need of re-assigning.

Once a GSSP boundary has been agreed upon, a "golden spike" is driven into the geologic section to mark the precise boundary for future geologists (though in practice the "spike" need neither be golden nor an actual spike). The first stratigraphic boundary was defined in 1977 by identifying the Silurian-Devonian boundary with a bronze plaque at a locality called Klonk, northeast of the village of Suchomastyin in the Czech Republic. GSSPs are also sometimes referred to as Golden Spikes.

GSSAs

Because defining a GSSP depends on finding well-preserved geologic sections and identifying key events, this task becomes more difficult as one goes farther back in time. Before 630 million years ago, boundaries on the geologic timescale are defined simply by reference to fixed dates, known as Global Standard Stratigraphic Ages.

See also:

• Type locality

External links

• The Global Boundary Stratotype Section and Point (GSSP): overview

References

• id="CITEREFGehlingJensenDroserMyrow2001">Gehling, James; Sören Jensen & Mary Droser et al. (March 2001), "Burrowing below the basal Cambrian GSSP, Fortune Head, Newfoundland", Geological Magazine 138 (2): 213-218, 1, DOI:10.1017/S001675680100509X, <[1]
  • Hedberg, H.D., (editor), International stratigraphic guide: A guide to stratigraphic classification, terminology, and procedure, New York, John Wiley and Sons, 1976
  The geological time scale is used by geologists and other scientists to describe the timing and relationships between events that have occurred during the history of Earth.
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  The International Commission on Stratigraphy concerns itself with stratigraphy on a global scale. It is the largest scientific body within the International Union of Geological Sciences.
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  The International Union of Geological Sciences (IUGS) is an international non-governmental organization devoted to international cooperation in the field of geology.

  About

  
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  Palaeontology redirects here. For the scientific journal, see Palaeontology (journal).

  
  
  Paleontology, palaeontology or palæontology (from Greek: paleo, "ancient"; ontos
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  Faunal stages are subdivisions of rock layers used primarily by paleontologists who study fossils rather than by geologists who study rock formations. Typically, a faunal stage will consist of a series of rocks that contain similar fossils.
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  Public transport, public transportation, public transit or mass transit comprise all transport systems in which the passengers do not travel in their own vehicles.
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  AirPort is a local area wireless networking brand from Apple Inc. based on the IEEE 802.11b standard (also known as Wi-Fi) and certified as compatible with other 802.11b devices. A later family of products based on the IEEE 802.11g specification is known as AirPort Extreme.
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  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 stratigraphic sections of rock which serve as references for boundaries on the geologic time scale.
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  Precambrian (Pre-Cambrian) is an informal name for the supereon comprising the eons of the geologic timescale that came before the current Phanerozoic eon. It spans from the formation of Earth around 4500 Ma (million years ago) to the evolution of abundant
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  The Cambrian is a major division of the geologic timescale that begins about 542 ± 1.0 Ma (million years ago) at the end of the Proterozoic eon and ended about 488.3 ± 1.7 Ma with the beginning of the Ordovician period (ICS, 2004).
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  Fortune Head is a headland located about 1.6 km from the town of Fortune on the Burin Peninsula, southeastern Newfoundland.
  
  A 410 m thick section of rock along its cliffs is designated the Global Boundary Stratotype Section and Point (or GSSP) representing the boundary
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  Newfoundland — pronunciation   (help info ) IPA: ['nuw fən 'lænd] (French: Terre-Neuve, Irish:
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  worldwide view of the subject.
  Please [ improve this article] or discuss the issue on the talk page.

  
  
  A nature reserve (natural reserve, nature preserve, natural preserve
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  Trichophycus pedum (or Treptichnus pedum; formerly Phycodes pedum) is regarded as the earliest wide-spread complex trace fossil. Its earliest appearance, which was contemporaneous with the last of the Ediacaran biota, is used to define the
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  Radiometric dating (often called radioactive dating) is a technique used to date materials, based on a comparison between the observed abundance of particular naturally occurring radioactive isotopes and their known decay rates.
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  The Silurian is a major division of the geologic timescale that extends from the end of the Ordovician period, about 443.7 ± 1.5 Ma (million years ago), to the beginning of the Devonian period, about 416.0 ± 2.8 Ma (ICS 2004).
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  Devonian is a geologic period of the Paleozoic era spanning from roughly 416 to 359 million years ago. It is named after Devon, England, where rocks from this period were first studied.
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  Klonk, southwest of Prague, Czech Republic, is the location of the Global Boundary Stratotype Section and Point (GSSP) which marks the boundary between the Devonian and Silurian periods on the geologic time scale.
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  Motto
  "Pravda vítězí"   (Czech)
  "Truth prevails"
  Anthem
  Kde domov můj
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  A Global Standard Stratigraphic Age, often abbreviated GSSA, is a chronological age used to define the boundaries between different periods or epochs on the geologic time scale.
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  In some natural sciences, type locality (Latin locus typicus) is the typical or representative location and is typically the first example of a newly discovered or described object. Often it is namesake for the term.
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  digital object identifier (or DOI) is a permanent identifier given to a document, which is not related to its current location. A typical use of a DOI is to give a scientific paper or article a unique identifying number that can be used by anyone to locate details of the paper, and
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