The unbearable lightness of hard-rock mining (was The half-trillion-

> At the boundary with the lithosphere, the temp of the
> surrounding rock rise to 500 to 1000 degrees Centigrade.
> No known material could even BEGIN to withstand the
> pressure of the overlying rock at anywhere near those
> depths and temps.

http://www.google.com/search?q=ultra+supercritical+coal+alloys+700%C2%
B0C

"Nickel-based alloys, e. g. Inconel, would permit 35 MPa/700C/720C"

How could the bottom of an open-pit mine sustain those temperatures
if it were exposed to open air? If it were still too hot for your
robots, why would you not simply throw some water on it?

Bingham is three-quarters of a mile deep:
http://en.wikipedia.org/wiki/Bingham_Canyon_Mine

I haven't heard of any Bingham miners burning up at the bottom.

> From NAtional Geographic:
> The ambitious new mining projects are "ultra-deep"
> mines with shafts that are deeper than 2.2 miles
> (3.5 kilometers) in the ground, where temperatures
> rise well over a hundred degrees Fahrenheit (55
> degrees Celsius) and rock shatters like glass.

Wouldn't an open-pit mine be easier to prosecute than a mine-shaft?
Why would one choose the latter if one were mining something as
common as granite?
http://en.wikipedia.org/wiki/Granite

> There is only a limited amount of mass we can access
> on this earth. This is [a] byproduct of
> gravity and limits to material strength.

Please explain, in regard to Earth's continents.