Group (stratigraphy)

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by RockMagnetist (talk | contribs) at 02:51, 29 September 2015 (-Category:Geology terminology; +Category:Geological units using HotCat). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

A group in stratigraphy is a lithostratigraphic unit, a part of the geologic record or rock column that consists of defined rock strata. Groups are generally divided into individual formations. Groups may sometimes be divided into "subgroups" and are themselves sometimes grouped into "supergroups".

Some well known groups of northwestern Europe have in the past also been used as units for chronostratigraphy and geochronology. These are the Rotliegend, Zechstein (both of Permian age), Buntsandstein, Muschelkalk, Keuper (Triassic in age), Lias, Dogger and Malm (Jurassic in age) groups. Because of the confusion this causes, the official geologic timescale of the ICS does not contain any of these names any longer.

See also

Links

  • "Chapter 5. Lithostratigraphic Units". International Commission on Stratigraphy. 2013–2014. Retrieved 4 June 2014. - 6. Group