Odd world generation

So I created a now world for the Cosmic Upgrade and when it loaded, the entire world was made of abyssalite!

After I took the screenshot, I activated sandbox mode and reveled the entire map, the points of interest generated correctly but the rest of the map 

was filled, top to bottom, with abyssalite.

I used the default game options and I didn't mess with the files, so I have no idea what caused this to happen.

I made another world to see if it would happen again, but it generated normally.

I attached the save file if you want to check it out.

Abyssalite world.sav