Okay I lied, there is WAY too many volcano's that were generated in my world gen. Don't know about the other generated features (have no basis with coloured trees) such as marble and the gems. Speaking of gems, OreDict support would be nice in the future.

Ex. Minimap screen shot: http://imgur.com/sPBURyV

I also extended out past the already generated chunks and the spawning rate appeared to be normal. Not sure if this is a known issue or if is just a unique case.

If it matters, I have my forge log, pastebin doesn't like the size though, it's quite big.

Using: Forge 931, PR 4.0.4.11, FMP #193, CodeChickenLib #40

Also, using EBXL and ATG (alternate terrain gen) if it matters.

They generate where there is lava. Must've been a lot there.

That explains it then. Just coincidence there is a lot of lava near the regenerated chunks compared to non-regenerated chunks then. My bad