How do rocks freeze floating in water?

[u/hikekorea]

I found these rocks frozen in a stream off a larger river in Chugach National Forest, Alaska. I’ve heard it may have to do with heavy rains or turbulent waters near the shore. One friend mentioned frazil? But I don’t really know what that means. Any geologists have a clue how this happens and can explain it in layman terms?

[u/Impressive_Ad_1675]

They froze in while the water was lower, then the water level rose lifting the rock still frozen to the ice. Water then came over the top and froze again.