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Geological time periods and events

You are visiting the homepage ( for the Geological time periods and events vocabulary of terms. The geotime vocabulary provides: Standard nomenclature for paleontological intervals of time and events based on GTS2004.

The geotime vocabulary is described by the canonical URI (the vocabulary is of rdf:type = skos:ConceptScheme). The preferred namespace prefix is "geotime" with namespace URI = and namespace URI When minting the geotime concepts here, each concept will have its own Wiki page with a definition and further descriptions. An overview of the concepts are (will be) presented here organized alphabetical by their group (skos:Collection). The first step when working with an already existing vocabulary (with external namespace URIs) is to import the concept identifier URIs to the Wiki. This is done using a special wiki page in the "MediaWiki" wiki-namespace and starting with "Smw_import_" followed by the local namespace prefix to be used by the Wiki. For the geotime concepts we use: MediaWiki:Smw_import_geotime. Concepts are organized into groups using skos:Collection. The geotime vocabulary of terms is declared as a skos:ConceptScheme.


The first version of the geotime vocabulary was created 2011-01-11 using the GBIF Vocabulary Service. The RDF resource for the geotime terms was initiated in early 2012 and last updated on 2012-06-01. The geotime vocabulary is still in Draft version, not yet published.

Why declared as a SKOS vocabulary

The VoMaG task group ( recommends that the content of Controlled Value Vocabularies be expressed in SKOS RDF to enable maximal RE-USE. A new draft SKOS RDF resource for geological time periods and events was developed and made available at This new and draft SKOS vocabulary provides the definitions for the concepts here to be re-used in controlled value vocabularies of geological time periods. This model allows for multiple controlled value vocabularies to re-use concepts from the same SKOS vocabularies. And each controlled value vocabulary may further mix and match concepts defined by different SKOS vocabularies, when this is useful.

Editoral note

Notice that the base URI for the GeoTime vocabulary (draft version) is "". Please make sure that you are only using element identifiers in this namespace, e.g. "". There may be copies of the vocabulary file on the Web which can be retrieved from other locations, but those locations should not be used as the basis of identifiers.

Scope note

The GeoTime vocabulary provides the ... (TODO: add some notes here on what the geotime vocabulary does and does not cover).


The geotime vocabulary is licensed as Creative Commons Public Domain license (CC0). You are free to copy, distribute and transmit the work, to remix or adapt the work (e.g. to import the ontology and create specializations of its elements), all without asking permissions. If you wish to provide attribution you may include the statement, This work is based on the GEOTIME vocabulary for Geological Time Periods and Events.

Controlled value vocabularies

The terms for this RDF Vocabulary were originally developed using the GBIF Vocabulary Server. The terms here are actually reverse-engineered from the controlled value vocabularies. These controlled value vocabularies will be updated with the re-used URIs from this RDF Vocabulary and deposited to the GBIF Resources Repository at


  • Edward Baker, Natural History Museum in London
  • Dag Endresen, Global Biodiversity Information Facility (GBIF)


  • Baker E, Johnson KG, Young JR (2011). The future of the past in the present: biodiversity informatics and geological time. ZooKeys 150:397-405. doi: 10.3897/zookeys.150.2350 [1]
  • Gradstein FM, Ogg JG, and Smith AG (2004). A geological time scale 2004. Cambridge University Press. ISBN: 9780521786737. doi:10.4095/215638 [2]
  • Gradstein FM, Ogg JG, Schmitz M, and Ogg G (2012). The Geologic Time Scale 2012. Elsevier. ISBN 978-0-44-459390-0.