文摘
Multiple textural types of epidote with disparate compositions in eclogite and amphibolites were recognized. Grain-scale Sr isotopic heterogeneities in amphibolites indicate multiple origins and flow behavior of the retrograde fluid. Retrograde fluid for growth of most amphibolite minerals was locally derived and flowed in a pervasive manner. Influx of gneiss-derived amphibolite-facies fluid was transient, episodic, and channelized with a long transport distance. In-situ Sr isotopes on Ep/Ap constrain isotopic (dis)equilibrium, fluid origin, and flow regimes in subduction-zone rocks.