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Geologic Unit Part Role
This file contains the CGI Geologic Unit Part role vocabulary, as defined by the IUGS Commission for Geoscience Information (CGI) Geoscience Terminology Working Group. This vocabulary includes terms to specify the role played by a constituent part of a geologic unit. These terms may be used to populate GeologicUnit.part.GeologicUnitPart.role, and GeologicUnit.composition.compositionPart.role. There are terms in this vocabulary that only apply to one or the other of these properties, but after an effort to create two separate vocabularies, it was decided to use a single vocabulary in order to avoid having the same concept in more than one closely related vocabulary. The duplication of applicable concepts in the two contexts (GeologicUnit.part.GeologicUnitPart.role and GeologicUnit.composition.compositionPart.role) arises because the model allows representation of complex geologic unit descriptions in more than one way. A complex geologic unit like a migmatite complex or a lithologically heterogeneous stratigraphic unit will have many different lithologic components. The simplest approach to representing the lithologic heterogeneity is to report a single GeologicUnit element with compositionParts for each lithologic component; the role on these compositionParts provides information about what kind of parts they are and perhaps something about their relationship, along with the kinds of rock they are composed of. A more complex alternative approach is to represent the various components each as GeologicUnit elements, each with compositionPart links to the rock type(s) composing that part. These component GeologicUnit elements are aggregated by GeologicUnit.part.GeologicUnitPart elements, with roles in the aggregation for each GeologicUnit part. The benefit of the more complex approach is that additional descriptive properties provided by the GeologicUnit content model can be assigned to each part, as well as GeologicRelations between the parts. The role of the compositionParts in these more 'disaggregated' GeologicUnit elements would be a simpler 'composition' kind of role, because the heterogeneous 'whole' unit would be described in GeologicUnitParts that are more lithologically homogeneous. Its a trade-off between simplicity and expressiveness.
2009-07-14. Generate SKOS encoding of vocabulary from Excel spreadsheet.
2009-12-07 SMR Update metadata properties for version, creator, title, and format. Change skos:HistoryNote to dc:source for information on origin of terms and definitions.
2010-02-08. SMR Clean up namespace declarations so concept URI's follow CGI URN scheme; concepts have URN, are not document fragments.
2010-02-13 Add narrower relationship links by adding skos:narrower link in Protege, defining skos:narrower as inverse of skos:broader, calculating with Pellet reasoner to add inferred axioms, and using 'file/Export inferred axioms as ontology' in Protege.
2010-09-26 SMR correct URI and title for vocabulary from compositionCategory to GeologicUnitPartRole
2010-11-28 SMR replace URN with http URI according to CGI URI scheme (see
2012-02-07 SMR update URI to replace numeric final token with English-language string as in original URN scheme.
2012-02-27 SMR Add skos:exactMatch triples to previous version identifiers with numeric final tokens. Declare exactMatch a kind of owl:objectProperty. minimal representation of equivalence of identifiers.
2012-11-24 SMR Update to 201211 version; add collection entity, check all pref labels are lower case, remove owl:NamedIndividual and Owl:Thing rdf:types.
2016-11-21 OLR regenerate SKOS-RDF file as part of migration to new vocabulary server. No changes to terms. Minor corrections to hierarchy from the previous 2012 version.
This file contains the 2016 SKOS-RDF version of the CGI Geologic Unit Part Role vocabulary. Compilation and review in MS Excel spreadsheet, converted to MS Excel for SKOS generation using SKOS_for_GA_from_XLS_2016.03.xslt

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