メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.1625000 45.2916667, 142.1687500 45.2916667, 142.1687500 45.2958334, 142.1625000 45.2958334, 142.1625000 45.2916667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral