A weathered sign in the Minnesota River Valley proudly proclaims: “World’s Oldest Rock.” Erected in 1975, it marks a 3.8-billion-year-old gneiss — or so scientists thought.

Called Lewisian gneiss, it’s the oldest rock in the UK. It’s found in the northwest extremity of the Scottish mainland and the Western Isles. The gneiss’s new home is in our gardens, where it forms ...

Diamond drilling has wrapped up on the Zone 2A and Rosie areas, and SJ Geophysics completed ground EM and Resistivity surveys ...