メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.9125000 42.1291667, 142.9187500 42.1291667, 142.9187500 42.1333333, 142.9125000 42.1333333, 142.9125000 42.1291667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral