メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.7000000 44.0375000, 141.7062500 44.0375000, 141.7062500 44.0416667, 141.7000000 44.0416667, 141.7000000 44.0375000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral