Color photo of the South Pole of Mars
http://www.geocities.com/woodlock2y/E1400179-80SouthPole.jpg
source;
http://barsoom.msss.com/moc_gallery/e13_e18/images/E14/E1400179.html
Layering is clearly evident. Bright white CO2 layer atop a grayer thicker buildup underneath that which would be water ice.
Woodlock
