Wow, these images are fantastic! There is so much going on in there. There is that beatufiul contact in the background in horton's pos 67. The resolution is so fine it is like being there! And, in 79, it looks like most of the in situ spherules are on stalks.
The dark sandy flow like features in 67 are amazing, I still don't get why they are doing that. But, I have one other terrestrial analogy, I've seen ice do that on a cliff face, if it is near equilibirum with metling and thawing. And, we need to rememebr those rocks are going to be relatively hot during the day, even if the air temperature is very low. The air is so thin you are not going to get much thermal energy transfer through convection, so it almost does not matter how cold the air is, it is too think to make a difference. The important temperature is the actual ground temperature, the rock itself. And, when it absorbs thermal energy from the sun, it can only radiate it directly as IR. It is almost like it is under a green houst. And, of course, evaporation, or sublimation, of water would be a BIG way for the ground to lose energy, if there is enough water in it, which I think there is.
There has got to be some water here, either as ice, or brine, or more likely absorbed into the sulfate matrix itself.
But, anyway, cliff faces will form these well defined vertical ice features, basically an icicle adhering to the rock face. Ice tends to form features that appear to flow just like water a lot of the time, anyone who lives in a cold climate knows what I am talking about. The surface melt and freeze action makes it do this.
But, anyway, this is great stuff!
