I'm not sure if this answers the question fully but the data is more similar to a "surface" than a curve or ploygon. The data consists of a location on the xy plane and an associated value. So it seems more like a contour plot or a heat map. How it differs from the other Oxyplot examples I've seen is that the domain (the set of all locations) is not rectangular. Another example might shows this more clearly:
From playing around with a ContourSeries examples it seems like the problem I'm having is that Oxyplot will interpolate over the entire domain rectangular domain (or a smaller rectangular subset defined by the ColumnCoordinates and RowCoordinates). Maybe there is a way to flag locations so they are not interpolated.