BGS Lexicon of Named Rock Units
has lower boundary definition
Comment"Property describes the lower boundary of the rock unit" language=en 
Label"has lower boundary definition" language=en 

namespaces used
bgsrBGS Schemas
bgsreBGS RCS Earth Material Classes
bgsrgBGS Geochronology
bgsrlBGS Lexicon of Named Rock Units
bgsrmBGS 1:625 000 Digital Geological Map
dctDublin Core terms
rdfResource Description Framework
rdfsResource Description Framework - Schema
skosSimple Knowledge Organization System
xsdXML Schema Data Type