Electrical Conductivity of KCl?H ₂ O Fluids in the Crust and Lithospheric Mantle

Evidence from diamond inclusions suggests that KCl-bearing fluids may be abundant in the subcratonic mantle and these also cause local anomalies of high electrical conductivity. We therefore measured conductivity aqueous containing 6.96, 0.74 0.075 wt% KCl using a hydrothermal anvil cell to 2.5 GPa 675°C, with piston-cylinder apparatus 5 900°C. found below 550°C, increasing pressure generally decreases solution conductivity, while at higher temperatures effect is opposite. However, pressures, H2O smaller than for NaCl, possibly due hydration shell collapse. The experimental data are described by two numerical models. first model (R2 = 0.999), preferable crustal conditions: log ? ?2.03 + 25.0 × T?1 0.923 c 0.990 ? ?0, where S/m, T temperature K, concentration wt%, density pure water (in g/cm3) given temperature. ?0 limiting molar S·cm2·mol?1): 1,377 – 1,082 6,883 102 2,471 105 T?2. second 0.986), applicable lithospheric mantle: ?1.52 357 0.865 1.72 same equation ?0. latter shows already traces fluid account mantle.