 | This articleneeds additional citations forverification. Please helpimprove this article byadding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "International Commission on Stratigraphy" – news ·newspapers ·books ·scholar ·JSTOR(February 2013) (Learn how and when to remove this message) |
| Abbreviation | ICS |
|---|---|
| Formation | 1974 |
| Type | INGO |
Region served | Worldwide |
Official language | English, French |
Parent organization | International Union of Geological Sciences (IUGS) |
| Website | stratigraphy |
TheInternational Commission on Stratigraphy (ICS), sometimes unofficially referred to as theInternational Stratigraphic Commission, is a daughter or majorsubcommittee grade scientific organization that concerns itself withstratigraphical,geological, andgeochronological matters, worldwide.
It is the largest subordinate body of theInternational Union of Geological Sciences (IUGS). The ICS is essentially a permanentworking subcommittee, which meets far more regularly than the quadrennial meetings scheduled by the IUGS, when it meets as a congress ormembership of the whole.
| Segments of rock (strata) inchronostratigraphy | Time spans ingeochronology | Notes to geochronological units |
|---|---|---|
| Eonothem | Eon | 4 total, half a billion years or more |
| Erathem | Era | 10 defined, several hundred million years |
| System | Period | 22 defined, tens to ~one hundred million years |
| Series | Epoch | 38 defined, tens of millions of years |
| Stage | Age | 101 defined, millions of years |
| Chronozone | Chron | subdivision of an age, not used by the ICS timescale |
One of its main aims, a project begun in 1974, is to establish a multidisciplinary standard and globalgeologic time scale that will easepaleontological andgeobiological comparisons region to region by benchmarks with stringent and rigorous strata criteria calledGlobal Boundary Stratotype Section and Points (GSSPs) within the fossil record. (i.e. section of therock record as of a core sample section or accessible exposed strata, which when a core sample are usually "trayed" in long pieces, also called "sections" about a meter in length.)
Additionally the ICS defines an alternative type of benchmark and criteria calledGlobal Standard Stratigraphic Ages (GSSAs) where the characteristics and dating criteria set solely byphysical sciences methods (such as magnetic alignment sequences, radiological criteria, etcetera.) as well as encouraging an international and open debate amongstEarth scientists in thepaleontology,geology,geobiology andchronostratigraphy fields, among others.
The International Commission on Stratigraphy has spawned numeroussubcommittee level organizations organized and mobilized on a local country-wide or regional basis that are the true working committees of the IUGS, and these do the field work, basis comparisons in conference or co-ordinationresearch committee meetings of local or wide-scale scope.
The ICS publishes various reports and findings as well as revised references periodically, summarized in theInternational Stratigraphic Chart, a combinedworking proposal andguideline-to-date released after the last ICS deliberations prior to the upcoming (next) meeting of the IUGS. Until the IUGS accepts the recommendations, they are unofficial since the IUGS parent approves or dismisses the individual deliberation reports of the ICS, which are presented as recommendations, and span dating and strata selection criteria, and related issues including nomenclatures. Inde facto everyday matters, the deliberative results reported out of any meetings of the ICS are widely accepted and immediately enter everyday use, except in the rare cases where they result in a strong body of dissenting opinion, which matters are resolved before the full IUGS.
One such controversy arose in 2009 when the ICS deliberated and decided that thePlioceneSeries of the current but unofficially namedQuaternaryPeriod should be shifted into theNeogeneSystem and Neogene Period.[2] Despite the strong debate,[3] the Quaternary saw official ratification as a geological unit from the IUGS in June 2009, placing its lower boundary to theGelasian Stage/Age at Monte San Nicola, Sicily, Italy (until then uppermost part of thePliocene Series/Epoch, and thus of theNeogene System/Period), 2.58 MaBP.[4]
In addition to publishing paper and document (PDF) versions of the International Stratigraphic Chart, the ICS also provides a machine-readable version of the chart formulated using theWeb Ontology Language (OWL) and, in particular,Time Ontology in OWL. The ICS'chart web page also provides an interactive version of the chart, based on the OWL data.
The logo of International Commission on Stratigraphy was designed after the Chinese character of "mountain", 山.
.png)
