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.
Next Figure | Table of Contents