The landscape around them was bleak, almost as devoid of plant life as the white sands had been.
But its waters become absorbed in the sands of the desert steppes before they reach the Caspian.
You find thus in the very sands an anticipation of the vegetable leaf.
It is marked by grey clays and sands, lignitic fossiliferous clays, beds of lignite or brown coal, sometimes 8 ft.
Some sands contain as much as 50% of air of nearly the same composition as atmospheric air.