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BGS Geochronology
A property that describes the method by which the age has been determined
age determination type
BGS Geological Time Boundary Age Determination Types
How a particular geological age was determined
Classifies dated geological events according to the authoritative reference for the dating, or by other methods used
A property that provides an age value in years before present
years before present
A property that provides the uncertainty on an age value in years
uncertainty (years)
A boundary between geological divisons of time
Geochronological Boundary
This schema defines named divisions of geological time.
BGS Geological Time Divisions
Geological time is divided into useful segments that are then further sub-divided. A well known example is the Jurassic, which is a Period, part of the (much longer) Mezosoic Era. The Jurassic Period is sub-divided into the Early, Mid and Late Jurassic Epochs. Some Eras are divided into sub-eras, similarly, Periods, Epochs and Ages can have sub-divisions.
An Ordered List of divisions of time
A property linking to the latest date (ie minimum age) of a geological time division.
minimum age
This property indicates the rank of the geological time division that it describes
rank
This property links a geological division of time to the older division of the same rank so that it it is possible to put each time division in the correct order
previous division
BGS Geological Time Division Ranks
The rank of a geochronological division specifies how large it is and what sort of sub-divisions it contains.
Geologists label divisions of geological time with named ranks which indicate which level of the hierarchy of terms they belong to. The preferred labels in this scheme are the chronological rank names; the equivalent stratigraphical rank name is provided as an alternative label.
This property links the name of a rank - a level of geological time division - to the ordered list of ranks that it is contained in. Ranks are ordered from the largest division level to the smallest.
in ordered list
An Ordered List of BGS Geochronostratigraphy ranks
http://data.bgs.ac.uk/id/Geochronology/Rank/AGE http://data.bgs.ac.uk/id/Geochronology/Rank/EON http://data.bgs.ac.uk/id/Geochronology/Rank/EPOCH http://data.bgs.ac.uk/id/Geochronology/Rank/ERA http://data.bgs.ac.uk/id/Geochronology/Rank/MIS http://data.bgs.ac.uk/id/Geochronology/Rank/PERIOD http://data.bgs.ac.uk/id/Geochronology/Rank/SUB-AGE http://data.bgs.ac.uk/id/Geochronology/Rank/SUB-EPOCH http://data.bgs.ac.uk/id/Geochronology/Rank/SUB-ERA http://data.bgs.ac.uk/id/Geochronology/Rank/SUB-PERIOD
A system by which geochronological divisions are defined
A property linking to the earliest date (ie maximum age) of a geological time division
maximum age
Geological time is divided into multiple levels of sub-division. This property links a given division to an ordered lists of its immediate child divisions.
subdivisions
next division
This property links a geological division of time to the younger one of the same rank so that it it is possible to put each time division in the correct order