BGS Lexicon - Class
Age Based

http://data.bgs.ac.uk/id/Lexicon/Class/AGE
Identifier"http://data.bgs.ac.uk/id/Lexicon/Class/AGE" language=en 
Comment"Unit classified according to age (or composite age or age range). E.g. Devonian rocks, undifferentiated. Always Informal." language=en 
Schemahttp://data.bgs.ac.uk/ref/Lexicon/Class
Label"Age Based" language=en 
Typehttp://www.w3.org/2004/02/skos/core#Concept
Is in schemehttp://data.bgs.ac.uk/ref/Lexicon/Class

namespaces used
bgsrBGS Schemas
bgsrgBGS Geochronology
bgsrlBGS Lexicon of Named Rock Units
dctDublin Core terms
rdfResource Description Framework
rdfsResource Description Framework - Schema
skosSimple Knowledge Organization System
xsdXML Schema Data Type