International Commission on Stratigraphy
Encyclopedia
The International Commission on Stratigraphy (ICS), sometimes referred to by the unofficial "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 scientific 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
.
that will ease paleontogical
and geobiological
comparisons region to region by benchmarks with stringent and rigorous strata criteria called Global Boundary Stratotype Section and Point
s (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.)
s (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.
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 this past year when the ICS deliberated and decided the Pliocene
series of the current but unofficially named Quaternary
period should be shifted into the Neogene
system
and period. 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
(3.6 mya) age. 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
.
Stratigraphy
Stratigraphy, a branch of geology, studies rock layers and layering . It is primarily used in the study of sedimentary and layered volcanic rocks....
, geological
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
, and geochronological
Chronology
Chronology is the science of arranging events in their order of occurrence in time, such as the use of a timeline or sequence of events. It is also "the determination of the actual temporal sequence of past events".Chronology is part of periodization...
matters on a global scale.
It is a subordinate body of the International Union of Geological Sciences
International Union of Geological Sciences
The International Union of Geological Sciences is an international non-governmental organization devoted to international cooperation in the field of geology.-About:...
—of which it is the largest scientific 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
Committee
A committee is a type of small deliberative assembly that is usually intended to remain subordinate to another, larger deliberative assembly—which when organized so that action on committee requires a vote by all its entitled members, is called the "Committee of the Whole"...
.
Aims
One of its main aims, a project begun in 1974, is to establish a multidisciplinary standard and global geologic time scaleGeologic time scale
The geologic time scale provides a system of chronologic measurement relating stratigraphy to time that is used by geologists, paleontologists and other earth scientists to describe the timing and relationships between events that have occurred during the history of the Earth...
that will ease paleontogical
Paleontology
Paleontology "old, ancient", ὄν, ὀντ- "being, creature", and λόγος "speech, thought") is the study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments...
and geobiological
Geobiology
Broadly defined, geobiology is an interdisciplinary field of scientific research that explores interactions between the biosphere and the lithosphere and/or the atmosphere....
comparisons region to region by benchmarks with stringent and rigorous strata criteria called Global Boundary Stratotype Section and Point
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...
s (GSSPs) within the fossil record. (i.e section of the rock record
Geologic record
The geologic record in stratigraphy, paleontology and other natural sciences refers to the entirety of the layers of rock strata — deposits laid down in volcanism or by sediment deposition of weathering detritus including all its fossil content and the information it yields about the history...
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
Additionally the ICS defines an alternative type of benchmark and criteria called Global Standard Stratigraphic AgeGlobal Standard Stratigraphic Age
In the stratigraphy sub-discipline of geology, a Global Standard Stratigraphic Age, officially abbreviated GSSA, is a chronological reference point and criterion in the world's rock records used to define the boundaries between different geological periods, epochs or ages on the overall geologic...
s (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
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
, geobiology
Geobiology
Broadly defined, geobiology is an interdisciplinary field of scientific research that explores interactions between the biosphere and the lithosphere and/or the atmosphere....
and chronostratigraphy
Chronostratigraphy
Chronostratigraphy is the branch of stratigraphy that studies the age of rock strata in relation to time.The ultimate aim of chronostratigraphy is to arrange the sequence of deposition and the time of deposition of all rocks within a geological region, and eventually, the entire geologic record of...
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.
Publishings
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 (PDF file, updated January 2008, compare with the [ICS-I.S. Chart of 2004]). 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 factoDe facto
De facto is a Latin expression that means "concerning fact." In law, it often means "in practice but not necessarily ordained by law" or "in practice or actuality, but not officially established." It is commonly used in contrast to de jure when referring to matters of law, governance, or...
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 this past year when the ICS deliberated and decided the Pliocene
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
series of the current but unofficially named Quaternary
Quaternary
The Quaternary Period is the most recent of the three periods of the Cenozoic Era in the geologic time scale of the ICS. It follows the Neogene Period, spanning 2.588 ± 0.005 million years ago to the present...
period should be shifted into the Neogene
Neogene
The Neogene is a geologic period and system in the International Commission on Stratigraphy Geologic Timescale starting 23.03 ± 0.05 million years ago and ending 2.588 million years ago...
system
System (geology)
A system in the natural sciences and stratigraphy is an idealized composite unit of the geologic record made up of a succession of rock layers that were laid down together within a certain corresponding geological time span, and are used in turn to date things to a certain corresponding geologic...
and period. 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
Messinian
The Messinian is in the geologic timescale the last age or uppermost stage of the Miocene. It spans the time between 7.246 ± 0.005 Ma and 5.332 ± 0.005 Ma...
to the Zanclean
Zanclean
The Zanclean is the lowest stage or earliest age on the geologic time scale of the Pliocene. It spans the time between 5.332 and 3.6 Ma ± 0.005 Ma . It is preceded by the Messinian age of the Miocene epoch, and followed by the Piacenzian age....
(3.6 mya) age. 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
Piacenzian
The Piacenzian is in the international geologic timescale the upper stage or latest age of the Pliocene. It spans the time between 3.6 ± 0.005 Ma and 2.588 ± 0.005 Ma...
(2.588 mya) or possibly the end of the Gelasian
Gelasian
The Gelasian is an age in the international geologic timescale or a stage in chronostratigraphy, being the earliest or lowest subdivision of the Quaternary period/system and Pleistocene epoch/series. It spans the time between 2.588 ± 0.005 Ma and 1.806 ± 0.005 Ma...
(1.806 mya), any of which are in a different epoch
Epoch (geology)
An epoch is a subdivision of the geologic timescale based on rock layering. In order, the higher subdivisions are periods, eras and eons. We are currently living in the Holocene epoch...
.