A possible UHP-eclogite in the Leaota Mts. (South Carpathians) and its history from high-pressure melting to retrograde inclusion in a subduction melange
作者： Gavril Săbău
DOI: 10.1016/S0024-4937(99)00094-8
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摘要: Abstract An unusual eclogite pod containing impure jadeite to omphacite pyroxene with anti-phase domain (APD) visible under the optical microscope is hosted in a medium-grade matrix Leaota Massif. Textural relationships support hypothesis of garnet formation by peritectic reactions involving high-jadeite clinopyroxene, while inclusions entrapped garnet, mainly wide range amphibole compositions, seemingly crystallised from fluid phase disequilibrium host. Thermobarometric estimates indicate UHP, HT peak conditions (2.8–3.2 GPa, 780–840°C) inconsistent those associated rocks, followed complicated exhumation path. The P–T-array retrograde path suggests syn-subduction and tectonic inclusion melange derived accretionary wedge. Partial melting subducting slab, which induces weakening, may be an effective mechanism detaching enclosing small pods metamorphic terrains.
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