Stratigraphic classification and nomenclature of igneous and metamorphic rock bodies

Abstract

Research Article| September 01, 1987 Stratigraphic classification and nomenclature of igneous and metamorphic rock bodies 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) 99 (3): 440–442. https://doi.org/10.1130/0016-7606(1987)99<440:SCANOI>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); Stratigraphic classification and nomenclature of igneous and metamorphic rock bodies. GSA Bulletin 1987;; 99 (3): 440–442. doi: https://doi.org/10.1130/0016-7606(1987)99<440:SCANOI>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 Stratified extrusive volcanic rocks and metamorphic rock bodies of distinct sedimentary or volcanic origin are generally recognized as lithostratigraphic units. Intrusive igneous rock bodies and nonstratiform bodies of metamorphic rocks of undetermined origin should also be recognized as such. All are defined, identified, and mapped on the basis of their distinguishing lithology, which is the diagnostic criterion for establishing lithostratigraphic units. The name of formal igneous and metamorphic lithostratigraphic units, both layered and non-layered, should be composed of an appropriate local geographic term combined with either (1) a unit-term indicating its rank—group, formation, member—or (2) a simple field lithologic term—granite, gneiss, schist—indicating its predominant rock type, or both. Rank terms are more clearly suited for layered extrusive volcanic rocks and for metamorphic rocks whose original sedimentary and/or extrusive volcanic derivation is readily recognizable. A simple field lithologic term may be more appropriate in the case of nonlayered intrusive igneous bodies or for metamorphic rocks of homogeneous lithology and undetermined origin. The term “complex” may be used for igneous and/or metamorphic rock bodies of heterogeneous and irregular lithology, whether or not having suffered strong and complicated deformation and/or metamorphism. 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.