Deadvlei means "dead marsh." The clay pan was formed through repeated flooding of the Tsauchab river, which allowed a forest of camel thorn trees to thrive in the middle of a valley surrounded by giant 1000' sand dunes. A millennium ago the climate changed and the dunes fully enclosed the valley causing the trees to die. The wood is preserved through the heat of the sun and lack of rainfall. At dawn the direct backlighting of the sun causes the sand to explode in color, and the blue sky reflects off the white clay pan. One of the wonders of the world in my view.