Landscaping mountain patches

[ven]

I was able to alter a bit of mountainous terrain by digging it. It gave out soil even though it only had like 5% of heath on the tile. The cause is not as straightforward as one may think since other tiles on the heath border gave stone and didn't change height, even when they had higher heath proportions. I don't know if bug or not.

[jorb]

You are standing on a soil tile half-covered by a mountain transition. Not a bug.