 | | Journal (article/letter/editorial) | | Alteration and Fluid Geochemistry of the Tongonan Geothermal Field, Philippines Graeme L. SCOTT Abstract: The...during the history of the Tongonan Geothermal Field. Thermal activity in the Tongonan area began in the Miocene...gas was released to a geothermal fluid and condensed in groundwater with geothermal steam. The condensate...hydrothermal eruptions. The output of gas to the geothermal fluid decreased, while the salinity (10,000 mg/kg...mg/kg or ~ 2 wt% NaCl) and the temperature of the geothermal fluid remained nearly constant throughout the |  | Bargar, Keith E., Keith, Terry E.C., Trusdell, Frank A., Evans, S.R., Sykes, M.L. (1996) Hydrothermal alteration mineralogy of SOH drill holes, Kilauea East Rift Zone geothermal area, Hawaii. Open-File Report Vol. 1996 (96-10) US Geological Survey doi:10.3133/ofr9610 | Report (issue) | | Mineralogy of SOH Drill Holes, Kilauea East Rift Zone Geothermal Area, Hawaii By Keith E. Bargar 1 , Terry E...FIGURES 1. Map showing the location of three SOH geothermal drill holes and the earlier HGP-A drill hole...euhedral and subhedral, analcime crystals, blocky prehnite crystal clusters, and a partial, thin coating...................................49 23. Blocky prehnite crystal clusters that formed later than platy...compared with drill holes in Iceland and other geothermal areas ...................................... |  | Bird, Dennis K., Schiffman, Peter, Elders, Wilfred A., Williams, Alan E., McDowell, S. Douglas (1984) Calc-silicate mineralization in active geothermal systems. Economic Geology, 79 (4) 671-695 doi:10.2113/gsecongeo.79.4.671 | Journal (article/letter/editorial) | | calc-silicates in geothermal systems areheulandite, laumontite,wairakite,prehnite,epidote,garnet,sphene...temperaturesbelow 200øC, whereaswairakite,epidote,prehnite,and actinoliteoccurwithin the rangeof temperaturesfrom...octahedralsubstitution of ferric iron for aluminumin epidotes,prehnite,and garnetand of ferrousiron for magnesiumin clinopyroxenes...disappearanceof one or more of the phasescalcite,prehnite,wairakite,or biotite. From the available data...andandradite garnets in thelattersystem andthe presenceof prehnite at Cerro Prieto. Introduction patternsof calc-silicatesare |  | | Report (issue) | | GEOLOGICAL SURVEY Estimated temperatures for geothermal drill holes at Medicine Lake Volcano, northeastern...volcano showing the location of 11 of the 12 geothermal prospect drill holes included in this study ...hydrothermal alteration minerals with depth in sampled geothermal drill holes of the Medicine Lake volcano area...27. Radiating, fan-shaped aggregates of blocky, prehnite crystals ........ .74 28. Tube-like opal deposits...actinolite/tremolite crystals and later, blocky, prehnite crystals, b. Fibrous to acicular actinolite/tremolite |  | | Report (chapter) | | Chicago on July 8, 2015 Environmental impact of geothermal energy utilization STEF/~N A R N O R S S O N...(e-mail stefanar@raunvis.hi.is) Abstract: Presently geothermal energy accounts for 0.25% of the annual world-wide...Extraction of heat from geothermal reservoirs involves drillings. Exploitation of geothermal resources is generally...it preferable as a source for power and heat. Geothermal energy exploitation has locally some adverse...and cause land subsidence. The development of geothermal fields must sometimes be evaluated against the |  | | Report (volume) | | the last years from several working groups in the field of experimental studies and spectroscopic work....the epdiote minerals, from low temperature in geothermal fields (Chapter 6, Bird and Spieler), to common...(Bonazzi et al. 1996), named after its locality Andros Island/Greece; dissakisite(Ce) (Grew et al. 1991), named...x Coexisting minerals: Grossularite-andradite, prehnite, pumpellyite and sodic amphibole also show Al-Fe3+...unpublished results), and in hydrothermal epidote from geothermal fields (Bird and Spieler 2004), and might in |
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