I really LOVE the idea of dynamic terrain deformation. Red Faction (the original) that used the GeoMod engine kept me enthralled for hours on end.
I thought a game that had a tie-in to the VERY popular show Gold Rush (about gold placer mining in Alaska) would be the right fit. While I can't exactly call my game Gold Rush, I figured that I could model the game after all the activities I see on the show. And with the rising popularity of the show (I think it's currently the #1 cable show), I might be able to get some traction. And who knows...maybe I can get Discovery Chanel to feature the game on the website or maybe buy it (they have games for some of their other shows).
Believe it or not, there are ZERO mining games out there....there are plenty of Dig Dug clones...which is about as far away from real mining as you get. My concept would center around the fact that you get (lease/buy?) a claim in the Alaskan Klondike. You need to buy/rent equipment, chose locations to dig, set up the machinery to 'extract' the gold (like washplants) and find as much gold as possible.
Now, Zynga could probably CRUSH me with some sort of 'MineVille' game but I can't run from every potential risk. I also figured that the social aspect could/should be integral. Would have ability to join or work other claims (those belonging to friends) or maybe share equipment or even (as the title implies) have to deal with others poaching your gold by mining your land without your permission.