It's just my guess, but it sounds like the "old guys" find the "gems/mines" drill & get samples & then pass the property off to a new group, who either start up a mine, or get it set up for sale to one of the really big guys. Startup of a mine is very expensive & takes time!! The "old guys" then move off to the next promise land, to hopefully find another "gem/mine", & go through the whole thing again... JMHO though......