Olivine‐bearing symplectites in fractured garnet from eclogite, Moldanubian Zone (Bohemian Massif) – a short‐lived, granulite facies event

摘要: Recent petrological studies on high-pressure (HP)–ultrahigh-pressure (UHP) metamorphic rocks in the Moldanubian Zone, mainly utilizing compositional zoning and solid phase inclusions garnet from a variety of lithologies, have established prograde history involving subduction subsequent granulite facies metamorphism during Variscan Orogeny. Two temporally separate events are developed rather than single P–T loop for HP–UHP amphibolite–granulite overprint Zone. Here further evidence is presented that occurred after had been exhumed to different levels middle or upper crust. A medium-temperature eclogite part series tectonic blocks lenses within migmatites contains well-preserved assemblage with omphacite zoned garnet. Omphacite partly replaced by symplectite diopside + plagioclase amphibole. Garnet equilibria pseudosection calculations indicate HP at relatively low temperature conditions ~600 °C 2.0–2.2 GPa. The striking feature presence porphyroblasts veins filled olivine, spinel Ca-rich plagioclase. These minerals occur as forming symmetric zones, central zone rich olivine separated host two marginal zones consisting small amounts spinel. Mineral textures show they were first mostly calcic amphibole, which was later transformed into assemblages. olivine-spinel temperatures ~850–900 °C pressure below 0.7 GPa. preservation assemblages implies short-lived process. new results point geodynamic model where amphibolite heating mantle-derived magma