New rock formation appearing under dirt dumping site upon removal of dump site

Describe the issue

I created a dirt only dump zone on the second level of the island, ground was all dirt when I started. Several years later I start to use the dirt pile to refill various sections of the lower area. On digging back to ground level sections of the original terrain have converted to rock from dirt, with the natural stone texture.

To Reproduce
Steps to reproduce the behavior:

1. Load attached saves 'Sixth Run Magic Rock' and 'Sixth Run Magic Rock 2'
2. Inspect excavation zone on tier 2 of island.
3. See new rock.

Expected behavior
terrain to remain the original material prior to existence of dump zone.

Additional context

• Game version: 0.2.11, however originally observed in 0.2.10a

Attachments

Sixth Run More Magic Rock 2.save
Sixth Run More Magic Rock.save

Files not imported: Sixth Run More Magic Rock 2.save, Sixth Run More Magic Rock.save

Thanks for reporting, this has been fixed for some time now :)