A hydrogeological and geochemical model of the high-temperature geothermal system of Amatitlan, Guatemala
- West Japan Engineering Consultants, Inc., Fukuoka (Japan)
- GeothermEx, Inc., Richmond, CA (United States); and others
Geological, geophysical and geochemical data from deep and shallow wells indicate the presence of a large geothermal system fed by upflow beneath Volcan de Pacaya, with source temperatures {ge} 330{degrees}C and chloride contents on the order of 2,500 mg/l. A considerable contribution of magmatic water is suggested by chemical and isotopic data, provided that water-rock interactions have substantially neutralized the acidity of the magmatic component. The areal extent of the upflow zone is unknown, and can only be delimited by further drilling to the south and southeast of deep well AMF-2, which encounters the two-phase upflow zone. Outflow is directed to the north, towards Lago de Amatitlan. The outflow path is long (more than 7 km), and lateral cooling occurs both via conduction and dilution with cool groundwater. Vertical cooling is also indicated by temperature reversals of up to 60{degrees}C beneath the outflow tongue, attributed to a regional underflow of cool groundwater. Outflow paths do not appear to be controlled by geologic structures or aquifers; instead, the hot water appears to {open_quotes}float{close_quotes} on top of the gently sloping unconfined groundwater table. These aspects of the geothermal system were used to develop the numerical model of the Amatitlan geothermal system, which is the subject of a separate paper.
- OSTI ID:
- 494377
- Report Number(s):
- CONF-960913-; TRN: 97:002642-0052
- Resource Relation:
- Conference: Annual meeting of the Geothermal Resources Council, Portland, OR (United States), 29 Sep - 2 Oct 1996; Other Information: PBD: 1996; Related Information: Is Part Of Geothermal development in the Pacific rim. Transactions, Volume 20; PB: 886 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
INEEL Subregional Conceptual Model Report; Volume 1 - Summary of Existing Knowledge of Natural and Anthropogenic Influences Governing Subsurface Contaminant Transport in the INEEL Subregion of the Eastern Snake River Plain
Hydrocarbon anomaly in soil gas as near-surface expressions of upflows and outflows in geothermal systems