Are holes down to the void normal in the "Deep Dark"?

In the "Deep Dark", I found what looked like a naturally generated hole straight down through the bedrock into the void, is that normal?

Here are some screenshots:

Also, throwing an item through work without problems ;-)

Are you sure it was a hole, and not just un-generated blocks? Sometimes a block will be generated as a barrier block, and will need a few minutes to load. Try tossing down an item, like dirt, and if it falls down, its just a glitch, and this shouldn't happen in any other worlds. If the dirt stays there, try walking on it, as this means it is just not loaded yet. If this occurs in any other worlds, and it is a hole, contact Mojang with a bug-report.

Yes, these great holes looking like created by TNT can naturally appear in the deep dark. They go down to bedrock. I don't know exactly, but I think they should end above bedrock so that there is no hole to the void. If the hole is square shaped then it's probably an unloaded chunk, which you can fix by quitting and reloading your world.