メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((143.1812500 42.9375000, 143.1875000 42.9375000, 143.1875000 42.9416667, 143.1812500 42.9416667, 143.1812500 42.9375000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral