メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4687500 43.5708334, 142.4750000 43.5708334, 142.4750000 43.5750000, 142.4687500 43.5750000, 142.4687500 43.5708334)) ^^http://www.opengis.net/ont/geosparql#wktLiteral