The system NaClCaCl2H2O: I. The ice liquidus at 1 atm total pressure

Laser microprobe analyses of Cl, Br, I, and K in fluid inclusions: Implications for sources of salinity in some ancient hydrothermal fluids

Boron isotope and concentration data are presented for hydrothermal fluids from different tectonic settings that reflect derivation of boron from marine evaporites (Red Sea brines), non-marine evaporites (Salton Sea), clastic sediments (Escanaba Trough and Guaymas Basin), back-arc basalts (Mariana Trough) and mid-ocean ridge basalts (21° and 11–13°N East Pacific Rise; Juan de Fuca Ridge; and 23° and 26°N, Mid-Atlantic Ridge). Boron isotope systematics of these fluids are used to constrain the δ″B-values of tourmalines found in ancient massive sulfide deposits and tourmalinitcs that formed under conditions analogous to those of modern hydrothermal systems. The data also provide insights into the physical conditions required for the formation of tourmaline in certain geologic environments.

Boron isotope systematics of hydrothermal fluids and tourmalines: A synthesis

A brine interface in the Salton Sea Geothermal System, California: Fluid geochemical and isotopic characteristics

Boron geochemistry of the lower crust: Evidence from granulite terranes and deep crustal xenoliths

The December 29–30, 1985, flow test of the State 2–14 well, also known as the Salton Sea Scientific drill hole, produced fluid from a depth of 1865–1877 m at a reservoir temperature of 305° ± 5°C. Another flow test at a depth of 3170 m produced brine contaminated by drilling fluid and diesel oil. Therefore we focus on the first flow test. Samples were collected at five different flashing pressures. The brines are Na-Ca-K-Cl-type waters with very high metal and low SO4 and HCO3 contents. Compositions of the flashed brines were normalized relative to the 25°C densities of the solutions, and an ionic charge balance was achieved by adjusting the Na concentration. The composition of the preflashed reservoir fluid was calculated using enthalpy-chloride relations applied to the normalized and charge-balanced brines. The calculated total dissolved solids in the preflashed reservoir fluid ranges from about 24.8 wt %, assuming insignificant thermal losses from the erupting fluid before sampling, to 26.0 wt %, assuming a 10% enthalpy loss by conduction of thermal energy through casing and surface piping. The preferred total dissolved solids of the reservoir fluid is 25.05 wt %. The calculated specific density of the preflashed reservoir fluid at 305°C and 1870 m depth ranges from 0.9980 (no thermal loss prior to sampling) to 1.0107 ± 0.0023 g cm−3 (10% thermal loss). Of the various cation geothermometers that are now in common use, the Na-K-Ca method gives a temperature (310°C) closest to the measured temperature (305°C) in the production horizon. Calculated Na/K geothermometer temperatures, using equations suggested by different investigators, range from 326° to 364°C. The Mg/K2 method gives a temperature of about 350°C, Mg/Li2 about 282°, and Na/Li 395°–418°C.

R. O. Fournier

Papers

Chemistry and Geothermometry of Brine Produced From the Salton Sea Scientific Drill Hole, Imperial Valley, California