Zircon from banded iron formation as a sensitive indicator of its polychronous background: a case study on the Kostomuksha greenstone belt, Karelian Craton, Fennoscandian Shield ...

• Main Authors: Slabunov, А.I., Kervinen, А.V., Nesterova, N.S., Maksimov, О.А., Medvedev, P.V.
• Format: Dataset
• Language: unknown
• Published: Taylor & Francis 2023
• Subjects: Genetics; FOS Biological sciences; Evolutionary Biology; Environmental Sciences not elsewhere classified; Chemical Sciences not elsewhere classified; Ecology; Biological Sciences not elsewhere classified; Developmental Biology; Cancer; Inorganic Chemistry; FOS Chemical sciences; Fennoscandian; karelian
• Online Access: https://dx.doi.org/10.6084/m9.figshare.24041572.v1; https://tandf.figshare.com/articles/dataset/Zircon_from_banded_iron_formation_as_a_sensitive_indicator_of_its_polychronous_background_a_case_study_on_the_Kostomuksha_greenstone_belt_Karelian_Craton_Fennoscandian_Shield/24041572/1

Zircon is not a common accessory mineral of banded iron formation (BIF), but it occurs in all BIF samples from the Kostomuksha Greenstone Belt (KGB) in the Karelian Craton of the Fennoscandian Shield. The Kostomuksha BIF is of Algoma type and is part of three variably old rock associations: BIF-1 is part of a sedimentary sequence in Mesoarchean (2.87–2.84 Ga) basaltic komatiites with dacites, BIF-2 is located in Meso-Neoarchean (2.8–2.79 Ga) felsic volcanics, and BIF-3 is part of a Neoarchean (2.76–2.74 Ga) greywacke unit with felsic volcanics. Analysis of zircon has revealed grains with cores and several generations of rims. The U-Th-Pb systems of zircon indicate that its isotopic age varies considerably from 2.98 to 1.89 Ga, forming up to 4 age clusters in each sample. Most samples contain single inherited grains. The bulk of zircon in BIF is younger than the host rocks and is interpreted as metamorphic. Most of metamorphic zircons display an oscillatory zoning, and their Th/U ratio varies from 0.01 to ...