Figure F47. Sr and Ba concentrations vs. weight percent CO₂ in metaperidotite samples from Leg 209. The samples with the highest Sr contents all include substantial proportions of carbonate; thus, carbonate minerals probably are the primary host for Sr in Leg 209 metaperidotites and much of the Sr may have been introduced during hydrothermal metasomatism. A few samples with high Ba and low CO₂ are impregnated peridotites, which include igneous plagioclase and clinopyroxene precipitated from melts migrating along grain boundaries. However, other samples with high Ba also have high CO₂ contents, consistent with the hypothesis that metasomatically introduced Ba in hydrothermal carbonate provides most of the Ba in the whole-rock budget for many Leg 209 metaperidotites.