Arkadia Underground Mining Areas?

I noticed that in the underground you get different resources in different sub-areas.
For example in the southeast you find mostly oil, while in the southwest dianthus is a more common find.

I was wondering if any of you already found out how many sub-areas there are? And where the borders of those areas are? Is the underground split in 4 or 9 subareas or aren't there any squares but is it the background colors on the map?

Any experienced underground miners care to comment?

 

each "color" give one set resourcer

Example is green give your telfium

View attachment 9333

 

Ahh excellent, thank you very much!