TY - JOUR

T1 - Eclogites of the Belomorian Mobile Belt: Geological-Petrological and Isotope-Geochemical Age Criteria

AU - Skublov, S. G.

AU - Berezin, A. V.

AU - Salimgaraeva, L. I.

PY - 2022/7/1

Y1 - 2022/7/1

N2 - 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.

AB - 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.

KW - Belomorian Mobile Belt

KW - eclogites

KW - isotopic age

KW - Lu-Hf method

KW - petrochronology

KW - Precambrian

KW - Sm-Nd method

KW - U-Pb method

KW - zircon

UR - http://www.scopus.com/inward/record.url?scp=85133345547&partnerID=8YFLogxK

U2 - 10.1134/S0016702922070047

DO - 10.1134/S0016702922070047

M3 - Article

AN - SCOPUS:85133345547

VL - 60

SP - 626

EP - 640

JO - Geochemistry International

JF - Geochemistry International

SN - 0016-7029

IS - 7

ER -