I have no idea what you were talking about after the first sentence and a half. Even here, your dates and numbers are wrong, though I suppose you could argue that a company (Phelps Dodge) employing nearly 14,000 people was a junior miner, but I would not. In 2006, they had revenue of 12 billion in a steeply improving market. The sale was concluded in 2007.
As of 2013 Kinross, 9th largest gold producer, employed 9,000 and had revenue of 19 billion. Freeport, who bough Phelps, employed 30,000 in 2013 and had the same revenue of 19 billion. Which one of these is generally considered a major while the other is not, and why? I don't know.
Looks like your "junior"(Phelps) wasn't so small after all, IMO.
BTW, the mining distric NNW of Tucson is Silverbell. Part of this range is what they call "sawtooth" and is visually dramatic and different for Arizona, almost Alps-like. ...should ask JB why the strategraphy is so different here.
VP