Unconformity-bounded stratigraphic units

Abstract

Research Article| February 01, 1987 Unconformity-bounded stratigraphic units: INTERNATIONAL SUBCOMMISSION ON STRATIGRAPHIC CLASSIFICATION (AMOS SALVADOR, Chairman) INTERNATIONAL SUBCOMMISSION ON STRATIGRAPHIC CLASSIFICATION (AMOS SALVADOR, Chairman) INTERNATIONAL SUBCOMMISSION ON STRATIGRAPHIC CLASSIFICATION (AMOS SALVADOR, Chairman) Search for other works by this author on: GSW Google Scholar GSA Bulletin (1987) 98 (2): 232–237. https://doi.org/10.1130/0016-7606(1987)98<232:USU>2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation INTERNATIONAL SUBCOMMISSION ON STRATIGRAPHIC CLASSIFICATION (AMOS SALVADOR, Chairman); Unconformity-bounded stratigraphic units: INTERNATIONAL SUBCOMMISSION ON STRATIGRAPHIC CLASSIFICATION (AMOS SALVADOR, Chairman). GSA Bulletin 1987;; 98 (2): 232–237. doi: https://doi.org/10.1130/0016-7606(1987)98<232:USU>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract An unconformity-bounded unit is a body of rock bounded above and below by specifically designated discontinuities in the stratigraphic succession (angular unconformities, disconformities, and so on), preferably of regional or interregional extent. Being bounded by stratigraphic discontinuities is the single diagnostic criterion used to establish and recognize unconformity-bounded units; they should be extended only as far as both of its bounding unconformities are identifiable. Unconformity-bounded units can be composed of diverse kinds of any class or classes of rocks—sedimentary, igneous, metamorphic, or any combination of two or more of these classes. Neither the lithologic character of the rocks that compose the unit, nor their fossil content, nor the time span it represents, however, enters into its definition and recognition. Unconformity-bounded units, therefore, are not lithostratigraphic, biostratigraphic, or chronostratigraphic units. They are what their name indicates—unconformity-bounded units, a distinct and separate kind of stratigraphic unit that requires separate recognition. The basic unconformity-bounded unit is the synthem. Synthems are given geographic names derived from features at or near the location where the unit is well developed. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.