メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.7875000 45.1000000, 141.7937500 45.1000000, 141.7937500 45.1041667, 141.7875000 45.1041667, 141.7875000 45.1000000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral