Indeed. For this reason, there is no point in mining tiles that are not and will not be in any city's radius (if your goal is to pop resources).
I believe each worked mine has a 1 in 10000 chance of popping a resource per turn, by the way - independent of game speed. Someone else can correct me on that if it's no longer the case, but I'm fairly sure it still holds.![]()
1 in 10000 per mining resource you have revealed - i.e. in later eras up to 6 in 10000 per turn
