I've only just started reading SWJ's website, recent...

I've only just started reading SWJ's website, recent presentations, announcements and watching their promo videos. Now I'm wondering the answers for two very fundamental questions.  Please excuse my laziness and enlighten me here ...

How does a historically very heavily mined area of land still contain lots of rich ore deposits near the ground surface?

If the land is this good, then how does a low cap company like SWJ end up owning that land or the right to mine it? 

I guess there is some interesting history that stopped the old mining operations, else it makes no sense. Too good to be true usually is.

Thanks in advance for your insights.