olympic dam project, page-14

Just trying(as most are I think!) to get my head around the whole process of Geothermal power generation.
If grade is king in mining(as we all know it is!) is the rocks temperature King as well?.The hotter the rocks the more volume of water you would be able to pump over and convert to steam(one would asssume!) and therefore have, after reducing pipeing diameter @ ground level, more pressure to drive turbines with.Throw in the depth of the Hot Rocks factor for a little more complication,as the depth increases,when the steam rises(and cools) the opportunity for steam to condense increases thus loseing the ability to drive turbines(?)
Upon the tubine being driven the steam(remaining) is condensed(what%?) and once again pumped down the hole through a series of non return valves(?)thus completing the loop(?)

interested in discussion Regards