Removing Aluminum Oxide from Carpet

My gas tank sits on a sheet of aluminum in the back of my boat, and due to not having it strapped down tight it bounced forward onto my carpeted floor while towing it. The bottom of the tank is covered in a fine black "soot" from rubbing on the aluminum, which in turn has created black stains on my carpet from the tank sliding around. Any ideas on how to remove this? Resolve doesn't seem to be doing the trick, so I was wondering if anyone else on this board has ever run into this problem.

Steve