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I am trying to extract geological information from the onegeology portal unfortunaley most of the data there only consists of WMS data.

For example, is it feasible to extract a particular legend class from

into a vector form? Or is the best that I can do is to use GDAL to translate the image into a geospatially referenced image?

Note -- OneGeologyPortal does allow for one to save the wms into kml/wmc but I am unable to open either in a GIS program(ArcGIS/QGis). Google Earth opens the file but the image resolution is severely deteriorated.

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As long as you access this data through the WMS protocol, I'm afraid you'll receive only raster (image data).

If this provider gives access to this data through vector formats/protocol (WFS, GML, Geojson, KML...), this would be the way to go.

About the "not working" KML file, have you simply tried to open it with Google Earth ?

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When I save using the onegeology portal into kmz, it tries to add the extension .kmz[1] which is not recognized by google earth. Manually changing that to .kmz produces an image readable by google earth however importing that to QGis gives me the error 'test.kml is not a valid or recognized data source'. ArcGIS gives me using kml to layer - 'Error 000401: No features were found for processing' – BJEBN Sep 7 '12 at 13:37
The extension issue is not really problematic, it is more than probably simply set by your browser. Renaming it is perfect. For Qgis, you should try to rename your test.kmz to, unzip it and then load the resulting KML file into QGIS. – niconoe Sep 7 '12 at 13:41
Unfortunatley, windows is unable to unzip as it does not contain anything. Looking at the source code of the kmz file I assume that it actually might just reference the original wms server location... – BJEBN Sep 7 '12 at 14:08

Try the WFS version (Web Feature Service)


or convert the Vector KML files to Shapefile

KML to Shape

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Thanks for finding the arizona dataset but I am actually more interested in the Nationwide map provided by the WMS through OneGeology... and the rest of the world. – BJEBN Sep 7 '12 at 13:43

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