メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.1312500 42.4958334, 141.1375000 42.4958334, 141.1375000 42.5000000, 141.1312500 42.5000000, 141.1312500 42.4958334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral