Grampians National Park, Victoria Australia This view is from the early stages of the Beehive falls to Mt. Difficult trail.
This is vaguely reminiscent of the desert varnish I remember from Utah and other parts of the southwestern US, but with a very gray cast to it rather than being nearly black. It's still quite visible which surfaces are 'new' by the orange and yellow hues. Of course by new I mean they've probably been exposed a few thousand years or less.