| Title | Geochemical and Isotopic Evaluation of San Marcos Geothermal Area, Guatemala |
|---|---|
| Authors | Alfredo Rene Roldan Manzo |
| Year | 1997 |
| Conference | PNOC-EDC Geothermal Conference |
| Keywords | |
| Abstract | San Marcos Geothermal Area lies in the San Marcos Caldera (Pleistocene age), an elliptic depression with axis about 13 and 9 km, in the western part of the country. Chemical and isotopic analyses were made to 60 spring samples with a surface temperature range from 15 "C to 95 "C (boiling point in the area) and two river samples were chemically analyzed. Results show that there are two different reservoirs; a deeper one with subsurface temperature around 250 "C (chloride content = 600 m a ) and a shallower one with subsurface temperature close to 200 "C (chloride content = 500 mg/l). Chemically the waters are of three types; sodium chloride, calcium bicarbonate and a mixture between them. Isotopically the sodium chloride water seems to be a mixture of 75 % meteoric water and 24 % andesitic water. Previous gas analyses confirm underground temperature and magmatic origin of the water. |