So I went to load my world I was working one, and I noticed some areas of water was red, black soul sand particles were slowly falling and my fortress had excessive amounts of skeletons and ghast inside

The distance fog would change between the dark grey green of soulsand valley back to normal and sometimes at certain angles would turn solid red

It looked as if the soul sand biome generated on the chunks around my save area and there was no block from the valley, just the effects and the mob spawns, so now ghast spawn in the over world