Felix' 
WoGE #481 looked impossible at first glance. It showed a karst area, most likely in China since that is where this specific type of karst surface is most common. Looking closer I saw that it was not quite as impossible as I first thought, and from then it didn't take very long to find the correct location.
This WoGE is similar: It is a dune. Yet there are enough distinguishing features to place it in a fairly limited area, and I have included one feature making the location unique.
 
As always, post a comment  with latitude and longitude and write something about the  (geologic/geographic/hydrographic) feature in the picture.  If you win,  you get to host the next one. If you do not have a blog of your own, many of the regulars are very willing to help by hosting your puzzle.
Previous WoGEs are collected by Felix on 
his blog and a 
KML file. 
After a week has gone, and with Easter holidays coming up, I think it is time for a hint:
I followed a stream upriver to the source, and I think I may have found the source of the black coating on the dunes. It also explains why there is a mine in such an inhospitable area, the source area is even worse!