largest non volcanic hot rocks res. in world

http://www.energy.edu.au/curr_files/eea_geothermal.html

Australia's Geothermal

Australia has the largest non volcanic hot rocks resources in the world. Its resources fall into two categories:

hydrothermal (from relatively hot ground water) and
hot rock resources
Where geothermal reservoir quality can be engineered, the result is called Enhanced Geothermal Systems (EGS). Both these resources are prevalent in Australia witrh the majority of current and forecast investment to explore for and demonstrate the potential of geothermal energy in Australia focussed on EGS.

At least two regions are being explored for hydrothermal resources:

Great Artesian Basin and
Otway Basin