Barium isotope fractionation during experimental formation of the double carbonate BaMn[CO3]2 at ambient temperature

In this study, we present the first experimental results for stable barium (Ba) isotope (Ba-137/Ba-134) fractionation during low-temperature formation of the anhydrous double carbonate BaMn[CO3](2). This investigation is part of an ongoing work on Ba fractionation in the natural barium cycle. Precipitation at a temperature of 21 +/- 1 degrees C leads to an enrichment of the lighter Ba isotope described by an enrichment factor of -0.11 +/- 0.06 parts per thousand in the double carbonate than in an aqueous barium-manganese(II) chloride/sodium bicarbonate solution, which is within the range of previous reports for synthetic pure BaCO3 (witherite) formation.