Sulfur Caves can generate on the surface

In areas of the world where the Weirdness/Ridges noise is particularly low (below about -1.25), Sulfur Caves will begin spawning on the surface.

Steps to Reproduce

Create a world with seed 121825627925 and teleport to -100, 100, -130.

Cause

Sulfur Caves are set to generate between -1.1 and -0.95 weirdness values. No other biome uses weirdness values below -1, so Sulfur Caves can take over surface biomes when the weirdness value gets low enough. This can easily be fixed by changing the weirdness range to be -1 to -0.95.