Hot dry rock geothermal energy makes use of hot fluids found naturally in basement rock; but such HWR conditions are rare. By far the bulk of the world’s geothermal resource base (over 98%) is in the form of basement rock that is hot but dry—with no naturally available water. This means that HDR technology is applicable almost everywhere on earth (hence the claim that HDR geothermal energy is ubiquitous). Typically, the temperature in those vast regions of the accessible crystalline basement rock increases with depth. This geothermal gradient, which is the principal HDR resource variable, ranges from less than 20 °C/km to over 60 °C/km,
Between the Buttons of something really special and he was messing it up. But the way Brian appeared to not give a shit is exactly what the band was about." Outtakes from this photo session were later used for the cover and inner sleeves of the 1972 ABKCO compilation release "More Hot Rocks (Big Hits & Fazed Cookies)". The back cover of "Between the Buttons" is dominated by a six-panel cartoon accompanied by a rhythmic poem drawn by drummer Charlie Watts. When Watts asked Oldham what the title of the album would be, he told him it was "between the buttons", a term