メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((138.4437500 36.1833333, 138.4500000 36.1833333, 138.4500000 36.1875000, 138.4437500 36.1875000, 138.4437500 36.1833333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral