ClipArt ETC
"Diagram of the progress of a dune, from a to be. The arrow flies with the wind. A live tree standing before the dune when it is at a will be buried by the advance to b. Another tree, previously killed and still covered by the dune, will be brought to light when it has reached b." -Johnson, 1910

Dune Progress

"Diagram of the progress of a dune, from a to be. The arrow flies with the wind. A live tree standing…