The search for major gold discoveries in Australia is heading deeper than ever before, pushing technology and drillers to their limits in some of the country's most remote locations. The challenge of digging deeper is underlined by two major gold mining operations in Western Australia's remote northern Goldfields. The owners of Australia's deepest gold mine, the historic Gwalia mine near Leonora, have announced expansion plans that will enable mining to advance more than 2km below the surface. Gold miner Northern Star Resources has also begun drilling what is set to be the deepest diamond-drill hole in Australian mining history. http://www.abc.net.au/news/2018-03-...-deeper-looking-for-major-discoveries/9495184 I wonder what the effect of mining 3km below the surface is on cost?
