I desaturated it a little bit and added some contrast. Not sure if that marble looking section is ice or not. It is not the rocks. I have taken 100s of pictures in this area before and have never seen this phenomenon. I thought it was "neat"
It's heat coming from the water as it enters the colder air above its surface. Usually looks like wispy smoke-ish spider webby sort of thing. It is not frost on leaves; the water would melt any frost captured on a leaf as soon as it made contact with the water.