Chronometric Age quick reference guide

This document is intended to be an easy-to-read reference the currently recommended terms that extend the Darwin Core standard with vocabulary for chronometric ages. This document is not part of the standard. It draws on the term names and definitions from the normative part of the standard and combines them with comments and examples that are not normative, but that are meant to help people to use the terms consistently. The category ChronometricAge corresponds to the parent class, which is a special category term used to group the rest of the terms for convenience. Comprehensive metadata for current and obsolete terms in human readable form are found in a list of terms document. CSV files with the full history of the terms, with horizontal and vertical lists of these terms and the schema for the Darwin Core Archive extension can be found in the Chronometric Age repository.

ChronometricAge

ChronometricAge Class
Identifierhttp://rs.tdwg.org/chrono/terms/ChronometricAge
DefinitionAn approximation of a temporal position (in the sense conveyed by https://www.w3.org/TR/owl-time/#time:TemporalPosition) that is supported via evidence.
CommentsThe age of a specimen and how this age is known, whether by a dating assay, a relative association with dated material, or legacy collections information.
ExamplesAn age range associated with a specimen derived from an AMS dating assay applied to an oyster shell in the same stratum; An age range associated with a specimen derived from a ceramics analysis based on other materials found in the same stratum; A maximum age associated with a specimen derived from K-Ar dating applied to a proximal volcanic tuff found stratigraphically below the specimen; An age range of a specimen based on its biostratigraphic context; An age of a specimen based on what is reported in legacy collections data.
chronometricAgeID Property
Identifierhttp://rs.tdwg.org/chrono/terms/chronometricAgeID
DefinitionAn identifier for the set of information associated with a ChronometricAge.
CommentsMay be a global unique identifier or an identifier specific to the dataset. This can be used to link this record to another repository where more information about the dataset is shared.
Exampleshttps://www.canadianarchaeology.ca/samples/70673
verbatimChronometricAge Property
Identifierhttp://rs.tdwg.org/chrono/terms/verbatimChronometricAge
DefinitionThe verbatim age for a specimen, whether reported by a dating assay, associated references, or legacy information.
CommentsFor example, this could be the radiocarbon age as given in an AMS dating report. This could also be simply what is reported as the age of a specimen in legacy collections data.
Examples27 BC to 14 AD, stratigraphically pre-1104
chronometricAgeProtocol Property
Identifierhttp://rs.tdwg.org/chrono/terms/chronometricAgeProtocol
DefinitionA description of or reference to the methods used to determine the chronometric age.
Comments
Examplesradiocarbon AMS, K-Ar dates for the lower most marker tuff, historic documentation, ceramic seriation
uncalibratedChronometricAge Property
Identifierhttp://rs.tdwg.org/chrono/terms/uncalibratedChronometricAge
DefinitionThe output of a dating assay before it is calibrated into an age using a specific conversion protocol.
Comments
Examples1510 +/- 25 14C yr BP, 16.26 Ma +/- 0.016
chronometricAgeConversionProtocol Property
Identifierhttp://rs.tdwg.org/chrono/terms/chronometricAgeConversionProtocol
DefinitionThe method used for converting the uncalibratedChronometricAge into a chronometric age in years, as captured in the earliestChronometricAge, earliestChronometricAgeReferenceSystem, latestChronometricAge, and latestChronometricAgeReferenceSystem fields.
CommentsFor example, calibration of conventional radiocarbon age or the currently accepted age range of a cultural or geological period.
ExamplesINTCAL13, sequential 6 phase Bayesian model and IntCal13 calibration
earliestChronometricAge Property
Identifierhttp://rs.tdwg.org/chrono/terms/earliestChronometricAge
DefinitionThe maximum/earliest/oldest possible age of a specimen as determined by a dating method.
CommentsThe expected unit for this field is years. This field, if populated, must have an associated earliestChronometricAgeReferenceSystem.
Examples100
earliestChronometricAgeReferenceSystem Property
Identifierhttp://rs.tdwg.org/chrono/terms/earliestChronometricAgeReferenceSystem
DefinitionThe reference system associated with the earliestChronometricAge.
CommentsRecommended best practice is to use a controlled vocabulary.
Exampleskya,mya,BP,AD,BCE,ka,Ma,Ga
latestChronometricAge Property
Identifierhttp://rs.tdwg.org/chrono/terms/latestChronometricAge
DefinitionThe minimum/latest/youngest possible age of a specimen as determined by a dating method.
CommentsThe expected unit for this field is years. This field, if populated, must have an associated latestChronometricAgeReferenceSystem.
Examples27
latestChronometricAgeReferenceSystem Property
Identifierhttp://rs.tdwg.org/chrono/terms/latestChronometricAgeReferenceSystem
DefinitionThe reference system associated with the latestChronometricAge.
CommentsRecommended best practice is to use a controlled vocabulary.
Exampleskya,mya,BP,AD,BCE,ka,Ma,Ga
chronometricAgeUncertaintyInYears Property
Identifierhttp://rs.tdwg.org/chrono/terms/chronometricAgeUncertaintyInYears
DefinitionThe temporal uncertainty of the earliestChronometricAge and latestChronometicAge in years.
CommentsThe expected unit for this field is years. The value in this field is number of years before and after the values given in the earliest and latest chronometric age fields within which the actual values are estimated to be.
Examples100
chronometricAgeUncertaintyMethod Property
Identifierhttp://rs.tdwg.org/chrono/terms/chronometricAgeUncertaintyMethod
DefinitionThe method used to generate the value of chronometricAgeUncertaintyInYears.
Comments
Examples2-sigma calibrated range, Half of 95% confidence interval
materialDated Property
Identifierhttp://rs.tdwg.org/chrono/terms/materialDated
DefinitionA description of the material on which the chronometricAgeProtocol was actually performed, if known.
Comments
ExamplesDouble Tuff, Charcoal found in Stratum V, charred wood, tooth
materialDatedID Property
Identifierhttp://rs.tdwg.org/chrono/terms/materialDatedID
DefinitionAn identifier for the MaterialSample on which the chronometricAgeProtocol was performed, if applicable.
Comments
Examplesdwc:materialSampleID: https://www.ebi.ac.uk/metagenomics/samples/SRS1930158
materialDatedRelationship Property
Identifierhttp://rs.tdwg.org/chrono/terms/materialDatedRelationship
DefinitionThe relationship of the materialDated to the subject of the ChronometricAge record, from which the ChronometricAge of the subject is inferred.
CommentsRecommended best practice is to use a controlled vocabulary.
ExamplessameAs (cases where the subject material was completely destructively subsampled to get the ChronometricAge), subsampleOf (cases where part of the original specimen was extracted as the material used to determine the ChronometricAge), inContextWith (cases where the ChronometricAge is inferred from materialDated, such as sediments or cultural objects, in related temporal context),stratigraphicallyCorrelatedWith (cases where the ChronometricAge is inferred from materialDated in a stratigraphically correlated context)
chronometricAgeDeterminedBy Property
Identifierhttp://rs.tdwg.org/chrono/terms/chronometricAgeDeterminedBy
DefinitionA list (concatenated and separated) of names of people, groups, or organizations who determined the ChronometricAge.
CommentsRecommended best practice is to separate the values in a list with space vertical bar space ( | ).
ExamplesMichelle LeFebvre | Neill Wallis
chronometricAgeDeterminedDate Property
Identifierhttp://rs.tdwg.org/chrono/terms/chronometricAgeDeterminedDate
DefinitionThe date on which the ChronometricAge was determined.
CommentsRecommended best practice is to use a date that conforms to ISO 8601-1:2019.
Examples1963-03-08T14:07-0600 (8 Mar 1963 at 2:07pm in the time zone six hours earlier than UTC). 2009-02-20T08:40Z (20 February 2009 8:40am UTC). 2018-08-29T15:19 (3:19pm local time on 29 August 2018). 1809-02-12 (some time during 12 February 1809). 1906-06 (some time in June 1906). 1971 (some time in the year 1971).
chronometricAgeReferences Property
Identifierhttp://rs.tdwg.org/chrono/terms/chronometricAgeReferences
DefinitionA list (concatenated and separated) of identifiers (publication, bibliographic reference, global unique identifier, URI) of literature associated with the ChronometricAge.
CommentsRecommended best practice is to separate the values in a list with space vertical bar space ( | ).
ExamplesPluckhahn, Thomas J., Neill J. Wallis, and Victor D. Thompson. 2020 The History and Future of Migrationist Explanation in the Archaeology of the Eastern Woodlands: A Review and Case Study of the Woodland Period Gulf Coast. Journal of Archaeological Research. https://doi.org/10.1007/s10814-019-09140-x
chronometricAgeRemarks Property
Identifierhttp://rs.tdwg.org/chrono/terms/chronometricAgeRemarks
DefinitionNotes or comments about the ChronometricAge.
Comments
ExamplesBeta Analytic number: 323913 | One of the Crassostrea virginica right valve specimens from North Midden Feature 17 was chosen for AMS dating, but it is unclear exactly which specimen it was.

UseWithIRI

For more information on UseWithIRI, see Section 2.5 of the RDF Guide.

chronometricAgeConversionProtocol Property
Identifierhttp://rs.tdwg.org/chrono/iri/chronometricAgeConversionProtocol
DefinitionThe method used to convert the uncalibratedChronometricAge into a chronometric age in years, as captured in earliestChronometricAge, earliestChronometricAgeReferenceSystem, latestChronometricAge, and latestChronometricAgeReferenceSystem.
CommentsTerms in the chronoiri namespace are intended to be used in RDF with non-literal objects.
Examples
chronometricAgeDeterminedBy Property
Identifierhttp://rs.tdwg.org/chrono/iri/chronometricAgeDeterminedBy
DefinitionA person, group, or organization that determined the ChronometricAge.
CommentsTerms in the chronoiri namespace are intended to be used in RDF with non-literal objects.
Examples
chronometricAgeProtocol Property
Identifierhttp://rs.tdwg.org/chrono/iri/chronometricAgeProtocol
DefinitionA method used to determine the chronometric age.
CommentsTerms in the chronoiri namespace are intended to be used in RDF with non-literal objects.
Examples
chronometricAgeUncertaintyMethod Property
Identifierhttp://rs.tdwg.org/chrono/iri/chronometricAgeUncertaintyMethod
DefinitionThe method used to generate the value of chronometricAgeUncertaintyInYears.
CommentsTerms in the chronoiri namespace are intended to be used in RDF with non-literal objects.
Examples
earliestChronometricAgeReferenceSystem Property
Identifierhttp://rs.tdwg.org/chrono/iri/earliestChronometricAgeReferenceSystem
DefinitionThe reference system associated with the earliestChronometricAge.
CommentsTerms in the chronoiri namespace are intended to be used in RDF with non-literal objects.
Examples
latestChronometricAgeReferenceSystem Property
Identifierhttp://rs.tdwg.org/chrono/iri/latestChronometricAgeReferenceSystem
DefinitionThe reference system associated with the latestChronometricAge.
CommentsTerms in the chronoiri namespace are intended to be used in RDF with non-literal objects.
Examples
materialDated Property
Identifierhttp://rs.tdwg.org/chrono/iri/materialDated
DefinitionThe material on which the chronometricAgeProtocol was actually performed.
CommentsTerms in the chronoiri namespace are intended to be used in RDF with non-literal objects.
Examples