Evidence of temperature increase of CO (sub 2) -bearing fluids from Aluto-Langano geothermal field (Ethiopia); a fluid inclusions study of deep wells LA-3 and LA-6
Evidence of temperature increase of CO (sub 2) -bearing fluids from Aluto-Langano geothermal field (Ethiopia); a fluid inclusions study of deep wells LA-3 and LA-6 (in Proceedings of the Eleventh European symposium on Fluid inclusions research (ECROFI XI), Benedetto De Vivo (editor) and Pierfranco Lattanzi (editor))
European Journal of Mineralogy (October 1992) 4 (5): 907-919
This geothermal field is located within one of the most active volcanic areas of the main Ethiopian rift system. Exploratory drilling has revealed the existence of high T (approx 335 degrees C) two-phase fluids at Aluto. This study is focused on two wells situated on the main upflow zone of the geothermal system. The presence of minerals such as calcite, chlorite, hematite, illite, quartz, sphene, epidote, garnet, prehnite, biotite and actinolite indicate a water-rock interaction of high intensity. Seven samples were selected from different depths for petrographic observation, microthermometry and crushing experiments. The evidence from the study demonstrates heating up of the system from approx 250 degrees C to the present-day T of 320-335 degrees C. This heating could be explained by an intake of high enthalpy fluid in the upflow of the system.