メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((142.4625000 43.4166667, 142.4687500 43.4166667, 142.4687500 43.4208334, 142.4625000 43.4208334, 142.4625000 43.4166667)) ^^http://www.opengis.net/ont/geosparql#wktLiteral