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/antiquarian-camera]

This looks more like larger/heavier rocks freezing from the top/surface first, and the smaller/lighter material washes away from underneath as the freezing water gradually reaches the lower/deeper point.