Of course such fossils are possible- we found them! What happens if a tree is half buried? If that tree dies it will rot (the part that is exposed) and that is what YECs are saying. If a lava flow buries a tree without burning it I would be impressed. If a mudslide buries it well that isn't gradual. There aren't many trees around sand dunes...
The whole point is it takes rapid burial to have any chance of fossilization.