メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.1625000 44.2333333, 142.1687500 44.2333333, 142.1687500 44.2375000, 142.1625000 44.2375000, 142.1625000 44.2333333)) ^^http://www.opengis.net/ont/geosparql#wktLiteral