Evaluation of the effective bulk composition (EBC) during growth of garnet

The calculated EBC for all samples (four epidote-free and four epidote-bearing) contains less MnO and FeO (or lower FeO/MgO) than the whole rock bulk composition. The CaO content of the EBC is lower than the whole rock bulk composition in all epidote-free samples and in two of the four epidote-bearing samples. It is proposed that the differences between the EBC and whole rock bulk composition are caused by the sluggish kinetics of dissolution of reactants rather than diffusive transport of nutrients to the garnet.