| When it rains in the mountain ranges that ring Death Valley, the water dissolves minerals from the rocks over and through which it passes on its way down to the valley floor. On the valley floor, the water forms a shallow lake | that evaporates rapidly, leaving behind a carpet of dissolved mineral salts. Through time, layer after layer of salt accumulates, forming a thick salt 'playa' deposit. The salts are white, but in the photo are covered with brown dust. |