メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.9812500 43.1375000, 141.9875000 43.1375000, 141.9875000 43.1416667, 141.9812500 43.1416667, 141.9812500 43.1375000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral