メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.3750000 42.3250000, 142.3812500 42.3250000, 142.3812500 42.3291667, 142.3750000 42.3291667, 142.3750000 42.3250000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral