World Generation Problem

I've just generate a world with superflat, but i have just crash suddenly. When I have open my minecraftlauncher again, I have this world : http://imgur.com/dRWEYMx This world can be downloadable from :

What I expected to happen was...:
I expected a superflat world with 64 sandstone layers (I'm french you know, it's very difficult to explain )

What actually happened was...:
I have crashed, and i had a broken world with a very strange generation

Steps to Reproduce:
1. Create a new world
2. go to game mode Creative, and More world options
3. select a superflat, with presets with this line : 2;7,64x24;1;village
4. generate the world !