A rapid transition from subduction to Barrovian metamorphism: geochronology of mafic-ultramafic relicts of oceanic crust in the Central Alps, Switzerland.

ABSTRACT: Relicts of subducted oceanic lithosphere provide key information for the tectonic reconstructions of convergent margins. In the Central Alps, such relicts occur as isolated mafic-ultramafic lenses within the migmatites of the southern Adula nappe and Cima-Lunga unit. Analysis of the major-, minor-, and accessory minerals of these ophiolitic relicts, combined with zircon and rutile U-Pb ages and zircon oxygen isotopes, allows the reconstruction of different stages of their complex evolution. The mafic-ultramafic suite in Valle di Moleno consists of chlorite-harzburgites associated with metarodingites and retrogressed eclogites. Relic omphacite and kyanite in retrogressed eclogites provide evidence for subduction-related metamorphism. Increasing X_Prp in the garnet mantle towards t

SUBMITTER: Lemke K 

PROVIDER: S-EPMC11364590 | biostudies-literature | 2024

REPOSITORIES: biostudies-literature