The International Commission on Stratigraphy ( ICS ), sometimes unofficially referred to as the " International Stratigraphic Commission ", is a daughter or major subcommittee grade scientific daughter organization that concerns itself with stratigraphical , geological , and geochronological matters on a global scale.
16-634: The Meghalayan age is the name given in 2018, by the International Commission on Stratigraphy , to the current age or latest geologic age – or uppermost stage of the Quaternary . It is also the upper, or latest, of three subdivisions of the Holocene epoch or series . This way of breaking down time is based only on geology; for example, it is unrelated to the three-age system of historical periods into which human development
32-413: A congress or membership of the whole . 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
48-598: A cultural shift caused by a global climate event makes it unique," according to Stanley Finney, Secretary General of the International Union of Geological Sciences . This age is named after the Northeast Indian state of Meghalaya , where the stalagmite was found that is used to mark out its years. The International Commission on Stratigraphy officially ratified this age in June 2018, along with
64-470: A reference, and/or with a substantial contribution to the development of geological sciences through history." International Commission on Stratigraphy It is the largest subordinate body of the International Union of Geological Sciences (IUGS). The ICS is essentially a permanent working subcommittee , which meets far more regularly than the quadrennial meetings scheduled by the IUGS, when it meets as
80-449: Is constantly being recycled by tectonic and weathering forces, and older rocks and especially readily accessible exposed strata that can act as a time calibration are rare. For more recent periods, a Global Boundary Stratotype Section and Point (GSSP), largely based on paleontology and improved methods of fossil dating, is used to define such boundaries. In contrast to GSSAs, GSSPs are based on important events and transitions within
96-664: Is sometimes divided. The Meghalayan begins 4,200 years BP ( c. 2251 BCE or 7750 HE ). Helama & Oinonen (2019) dated the start of the Meghalayan to 2190–1990 BCE. The age began with a 200-year drought that impacted human civilizations in the Eastern Mediterranean , Mesopotamia , the Indus Valley and the Yangtze River Valley . "The fact that the beginning of this age coincides with
112-472: The International Commission on Stratigraphy (ICS) under the auspices of their parent organization, the International Union of Geological Sciences (IUGS), and are used primarily for time dating of rock layers older than 630 million years ago , lacking a good fossil record . The geologic record is more restricted before about 539 million years ago. This is because the Earth's crust in geological time scales
128-644: 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,
144-766: The Neogene System and Neogene Period. Despite the strong debate, the Quaternary saw official ratification as a geological unit from the IUGS in June 2009, placing its lower boundary to the Gelasian Stage/Age at Monte San Nicola, Sicily, Italy (until then uppermost part of the Pliocene Series/Epoch, and thus of the Neogene System/Period), 2.58 Ma BP . In addition to publishing paper and document (PDF) versions of
160-556: 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. The ICS publishes various reports and findings as well as revised references periodically, summarized in
176-562: 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.) 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
SECTION 10
#1732772015545192-687: 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. A worldwide multidisciplinary effort has been ongoing since 1974 to define such important metrics. The points and strata need be widespread and contain an identifiable sequence of layers or other unambiguous marker (identifiable or quantifiable) attributes. GSSAs are defined by
208-722: The International Stratigraphic Chart, the ICS also provides a machine-readable version of the chart formulated using the Web 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. Global Standard Stratigraphic Age In
224-792: The Mawmluh Cave site being the "GSSP of the youngest unit of the geologic time scale associated with dramatic climate changes with implications on human civilisation" the International Union of Geological Sciences (IUGS) included the GSSP of the Meghalayan Stage in the Mawmluh Cave in its assemblage of 100 "geological heritage sites" around the world in a listing published in October 2022. The organisation defines an IUGS Geological Heritage Site as "a key place with geological elements and/or processes of international scientific relevance, used as
240-502: 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
256-579: The earlier Greenlandian and Northgrippian ages/stages. Its Global Boundary Stratotype Section and Point (GSSP) is a Krem Mawmluh Cave formation in Meghalaya . Mawmluh cave is one of the longest and deepest caves in India, and conditions there were suitable for preserving chemical signs of the transition in ages. The global auxiliary stratotype is an ice core from Mount Logan in Canada. In respect of
#544455