Transition metal salts
by mschwamb scientist, translator
No salts we believe. There is no water involved in these processes. The blue is actually carbon dioxide frost we thinking comes of the geyser that lofts the dust and dirt from the base of the sublimating carbon dioxide ice sheet to the surface. The dark material is the dirt and dust and we think that is being blown by the surface winds. If you see more of these blue streaks or blue material around fans or blotches, please mark them with the interesting feature tool and highlight them in talk with #frost. Learn more about the the geysers and fans here and here. Learn more about interesting features to mark here.