メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.3875000 43.4791667, 141.3937500 43.4791667, 141.3937500 43.4833333, 141.3875000 43.4833333, 141.3875000 43.4791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral