| Title | Stable Isotope Geochemistry of Thermal Fluids from Lassen Volcanic National Park, California |
|---|---|
| Authors | Janik, Cathy J.; Nehring, Nancy L.; Truesdell, Alfred H. |
| Year | 1983 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | Exploration; USA; California; Geochemistry; Isotopes |
| Abstract | In the Lassen vapor dominated geothermal system, surface manifestation of thermal fluids at high elevations (1800-2500 m) include superheated and drowned fumaroles, steam heated acid sulfate hot springs. Neutral high chloride hot water discharges at lower elevations (1530-1570 m). Deuterium and oxygen 18 data establish genetic connection between these fluids and with local meteoric waters. Deuterium contents of high chloride thermal waters and superheated fumarolic stem are similar to those meteoric waters on the composite cone of the Lassen volcanic center, suggesting that recharge to the system occurs in this region. Steam from the highest temperatures fumarole at Bumpass Hell (apparently the area of major thermal upflow) and water from the highest chloride hot spring (Growler) have isotopic compositions corresponding to vapor limited equilibrium at 235°C. |