> In the mantle, temperatures range between 500 to 900 °C (932 to 1,652 °F) at the upper boundary with the crust; to over 4,000 °C (7,230 °F) at the boundary with the core. [1]
Those would be some pretty extreme extremophiles!
> However, it is thought unlikely that microbes could survive at temperatures above 150 °C, as the cohesion of DNA and other vital molecules begins to break down at this point. [2]
Aww man! Though there are some pretty amazing extremophiles out there anyway!
[1] http://en.wikipedia.org/wiki/Mantle_%28geology%29#Temperatur...