Eclogites of the Belomorian Mobile Belt (BMB) are a key object for geodynamic reconstructions not only of the BMB, but also of the entire Fennoscandian Shield. One of the main issues for BMB eclogites is the establishment of the time of their formation. The interpretation of the age of the BMB eclogites as Archean allowed some researchers to extend the geodynamic mechanisms of modern-type plate tectonics to this segment of the Archean crust. At present, the geochronological data obtained on the BMB eclogites are interpreted in different ways. Despite numerous publications on the age problem of the Belomorian eclogites (over 70 papers), a generalized overview of all points of view on the timing of eclogite metamorphism with critical analysis of underlying arguments is absent. The author’s interpretation of the age of eclogite metamorphism within the BMB is based on a combination of independent isotope-geochemical dating methods: local U-Pb dating of heterogeneous zircons with magmatic cores and eclogite rims, Lu-Hf and Sm-Nd dating of rock-forming minerals of eclogite paragenesis (garnet and omphacite). All three methods independently determine the age of eclogitic metamorphism as Svecofennian, with the same value of about 1900 Ma.
Original languageEnglish
Pages (from-to)626-640
Number of pages15
JournalGeochemistry International
Volume60
Issue number7
DOIs
StatePublished - 1 Jul 2022
Externally publishedYes

    Research areas

  • Belomorian Mobile Belt, eclogites, isotopic age, Lu-Hf method, petrochronology, Precambrian, Sm-Nd method, U-Pb method, zircon

ID: 113709491