メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.4750000 35.5916667, 138.4812500 35.5916667, 138.4812500 35.5958334, 138.4750000 35.5958334, 138.4750000 35.5916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral