<The clincher for me, though, that these streaks are probably something other than dust slides was the lightening of streaks' color over time that can be inferred by the observation that darker streaks overlay lighter streaks and never the reverse.


Hi Lan,

I find nothing strange about this. Cosider you have this cold landscape with CO2 frost on the top surface (or perhaps H2O) the dust slides and there goes the crystalized frost. . . you then have the darker natural soild exposed underneath. Which then slowly has the frost deposited on it again as time goes on and its get lighter.

in these photos here you of mount adans in washington you see that after the debris avalanche the soild beneath is darker than the surounding soil. this was observed and noted.