I was in a snowy tundra biome when I came across a chunk that was completely invisible, except from the edges, which were visible but they went invisible about halfway down the y coordinate from where I was. I tried to place gravel into it by sneaking on the edge, but they just dropped as an item. Granite did the same thing, I then put all my things into a chest and jumped into the chunk. The result was I started falling really fast for a split second,, then I started shaking up and down really rapidly. I could still move forward and back, but I kept shaking. Then I exited out of the game then came back into it and it was gone. I also counted how big it was and it was 16 by 16 (A chunk).

An igloo was also nearby by about 10 blocks but I don't know if that is significant.