メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.3000000 43.1500000, 141.3062500 43.1500000, 141.3062500 43.1541667, 141.3000000 43.1541667, 141.3000000 43.1500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral