メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((141.5625000 42.9500000, 141.5687500 42.9500000, 141.5687500 42.9541667, 141.5625000 42.9541667, 141.5625000 42.9500000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral