The Info List - International Commission On Stratigraphy

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The International Commission on Stratigraphy
(ICS), sometimes referred to by the unofficial name "International Stratigraphic Commission" is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigraphy, geological, and geochronological matters on a global scale. It is a subordinate body of the International Union of Geological Sciences—of which it is the largest body within the organisation—and of which it is essentially a permanent working subcommittee that meets far more regularly than the quadrennial meetings scheduled by the IUGS, when it meets as a congress or membership of the whole.


1 Aims 2 Methodology 3 Publications 4 References 5 External links


Units in geochronology and stratigraphy[1]

Segments of rock (strata) in chronostratigraphy Time
spans in geochronology 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 34 defined, tens of millions of years

Stage Age 99 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 global geologic time scale that will ease paleontological and geobiological comparisons region to region by benchmarks with stringent and rigorous strata criteria called Global Boundary Stratotype Section and Points (GSSPs) within the fossil record. (i.e. section of the rock 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.) Methodology[edit] Additionally the ICS defines an alternative type of benchmark and criteria called Global Standard Stratigraphic Ages (GSSAs) where the characteristics and dating criteria set solely by physical sciences methods (such as magnetic alignment sequences, radiological criteria, etcetera.) as well as encouraging an international and open debate amongst Earth scientists in the paleontology, geology, geobiology and chronostratigraphy fields, among others. The International Commission on Stratigraphy
has spawned numerous subcommittee 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-ordination research committee meetings of local or wide-scale scope. Publications[edit] The ICS publishes various reports and findings as well as revised references periodically, summarized in the International Stratigraphic Chart, a combined working proposal and guideline-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. In de 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 the Pliocene
Series of the current but unofficially named Quaternary
Period should be shifted into the Neogene
System and Neogene
Period.[2] The term Quaternary
has yet to be officially adopted by the IUGS, but has widespread support as acceptable nomenclature for the current geologic period beginning at the GSSP accepted at 5,332,000 years ago at the transition between the Messinian
Age to the Zanclean Age (3.6 mya). The ICS voted, perhaps because the time units span human paleo-archaeological strata, to begin the Quaternary
at the end GSSP
of the Piacenzian Age (2.588 mya) or possibly the end of the Gelasian (1.806 mya), any of which are in a different epoch. References[edit]

^ Cohen, K.M.; Finney, S.; Gibbard, P.L. (2015), International Chronostratigraphic Chart (PDF), International Commission on Stratigraphy . ^ Riccardi, A.C. (30 June 2009). "Ratification of the definition of the base of Quaternary
System/Period (and top of the Neogene System/Period), and redefinition of the base of the Pleistocene Series/Epoch (and top of the Pliocene
Series/Epoch)" (PDF). International Union of Geological Sciences. Retrieved 30 December 2011. 

External links[edit]

"www.stratigraphy.org". Retrieved 2018-01-19.  "International Chronostratigraphic Chart". stratigraphy.org. Archived from the original on 2014-05-30. Retrieved 2018-01-19.  "ICS Subcommission for Stratigraphic Information at Purdue University". Retrieved 2018-01-19. 

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measurement and standards

Chronometry Orders of magnitude Metrology

International standards

Coordinated Universal Time


UT ΔT DUT1 International Earth Rotation and Reference Systems Service ISO 31-1 ISO 8601 International Atomic Time 6-hour clock 12-hour clock 24-hour clock Barycentric Coordinate Time Barycentric Dynamical Time Civil time Daylight saving time Geocentric Coordinate Time International Date Line Leap second Solar time Terrestrial Time Time
zone 180th meridian

Obsolete standards

Ephemeris time Greenwich Mean Time Prime meridian

in physics

Absolute time and space Spacetime Chronon Continuous signal Coordinate time Cosmological decade Discrete time and continuous time Planck time Proper time Theory of relativity Time
dilation Gravitational time dilation Time
domain Time
translation symmetry T-symmetry


Clock Astrarium Atomic clock Complication History of timekeeping devices Hourglass Marine chronometer Marine sandglass Radio clock Watch Water clock Sundial Dialing scales Equation of time History of sundials Sundial
markup schema


Astronomical Dominical letter Epact Equinox Gregorian Hebrew Hindu Intercalation Islamic Julian Leap year Lunar Lunisolar Solar Solstice Tropical year Weekday determination Weekday names

Archaeology and geology

Chronological dating Geologic time scale International Commission on Stratigraphy

Astronomical chronology

Galactic year Nuclear timescale Precession Sidereal time

Other units of time

Flick Shake Jiffy Second Minute Moment Hour Day Week Fortnight Month Year Olympiad Lustrum Decade Century Saeculum Millennium

Related topics

Chronology Duration


Mental chronometry Metric time System time Time
value o