 The solution of metal, salts and water produced by diagenesis is produced at temperatures between 150 - 350°C.Hydrothermal fluid compositions are estimated to have a salinity of up to 35% NaCl with metal concentrations of 5-15 ppm Zn, Cu, Pb and up to 100ppm Ba and Fe.High metal concentrations are able to be carried in solution because of the high salinity.