Figure 4: Mixing lines of formate and acetate versus Mg for the Kulo Lasi fluids. Note that the reference deep-sea water sample (FU-PL05-TiG2 noted as SW here) was taken at 1150 m depth above the southern wall of the caldera (see Figure 1 for location and Table 3) and thus very likely within the plume [7]. This would account for the unusual concentrations of formate and acetate detected.