メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.4250000 42.5791667, 141.4312500 42.5791667, 141.4312500 42.5833333, 141.4250000 42.5833333, 141.4250000 42.5791667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral