| Title | Hydrothermal Mineralogy and Isotopic Geochemistry in the Cerro Prieto Geothermal Field, Mexico, I: Hydrothermal Mineral Zonation |
|---|---|
| Authors | Hoagland, James R.; Elders, Wilfred A. |
| Year | 1978 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | Exploration; Mexico; Cerro Prieto; Hydrologic; Quartz |
| Abstract | Hydrothermal mineral assemblages at Cerro Prieto reveal a consistent pattern of progressive response to elevated temperatures. Three stages can be recognized: (1) Diagenetic -- low temperatures; (2) Illite-chlorite -- above 150°C; (3) Calcaluminum silicate -- above 250°C, further subdivided by the first occurrence of epidote at 250°C, of prehnite and actinolite at 300°C and of biotite at 325°C. Below 300°C two other mineral assemblages occur which are into diagnostic of temperature. A zone of quartz and adularia is characteristic of hydrothermal discharge and a zone of calcite +- anhydrite seem to be characteristic of hydrothermal recharge. Mapping these mineral zones across the geothermal field helps to delineate its temperature distribution and hydrology. Somewhat similar mineral assemblages may be recognized in other geothermal fields in the Salton Trough which have formed in similar environments. |