The stratigraphy, alteration mineralogy and temperature conditions in well IDDP-1 were established through drill cutting analyses and geophysical logs. The stratigraphy comprises basaltic lava and hyaloclastite sequences extending to 1362 m succeeded by an intrusive complex. Intrusions comprise basaltic dykes, dolerites and below 2020 m, granophyre and felsites. Rhyolitic magma was intersected below 2100 m. Alteration reflects cooling in the upper similar to 1500 m of the reservoir. Below 1600 m temperature follows the boiling-point-depth curve. Alteration minerals are scarce in vicinity to the feed zone at 2035-2080 m correlating with a superheated steam zone above the magma, but estimated bottom-hole temperature is similar to 500 degrees C. (C) 2013 Elsevier Ltd. All rights reserved.