overlay a filled contour on world()

Hi,

Is it possible to overlay over a world region drawn by function world(),
a filled.contour for that specific region?

I've managed to do the inverse, add world to a filled.contour, but the
appearence of the map is not the one I would like. With contour() is
easy to do the task, but with filled.contour...

Any hints aprreciated

Cheers,

Antonio Rodr?guez


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