Geochemical and textural investigations of the Eoarchean Ukaliq supracrustals, Northern Québec (Canada)

• Published in: Lithos
• Main Authors: Chowdhury, Wriju, Trail, Dustin, Guitreau, Martin, Bell, Elizabeth, Buettner, Jacob, Mojzsis, Stephen
• Other Authors: Department of Earth and Environmental Sciences Rochester, University of Rochester USA, Laboratoire Magmas et Volcans (LMV), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement et la société-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Université Jean Monnet Saint-Étienne (UJM), Earth, Planetary and Space Sciences, University of California, Los Angeles, CA, USA, Department of Geological Sciences, University of Colorado, UCB 399, 2200 Colorado Avenue, Boulder, CO 80309-0399, Hungarian Academy of Sciences (MTA), ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: Inukjuak domain; Ukaliq Supracrustal Belt; Eoarchean; Zircon; Thin section images; Silicon isotopes; U-Pb geochronology; Lusingle bond; Hf isotopes; U-Pb geochronology and Lu-Hf isotopes; [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; Canada; Inukjuak; Porpoise Cove
• Online Access: https://hal.uca.fr/hal-03101296; https://hal.uca.fr/hal-03101296/document; https://hal.uca.fr/hal-03101296/file/Chowdhury-postprint.pdf; https://doi.org/10.1016/j.lithos.2020.105673

co-auteur étranger International audience Structural, geochronological and geochemical studies of pre-3.75 Ga rocks of volcano-sedimentary protoliths in the Inukjuak domain in the Superior Province in Québec have been mostly focused on the Nuvvuagittuq Supracrustal Belt (NSB). The Porpoise Cove outcrops – at the southwestern limit of the NSB – are the de-facto “type locality” for the supracrustals of the Inukjuak Complex. Yet, it remains unclear whether the NSB rocks are geochemically distinct from, or are in fact common to, a host of other supracrustal enclaves locked in the dominantly gneissic Inukjuak domain. Here, we report detailed textural and geochemical studies for a suite of rocks from the Ukaliq Supracrustal Belt (USB), located approximately 3 km northeast of the NSB. We find that the USB and NSB have a similar protracted metamorphic history; both experienced amphibolite grade metamorphism and contain granitoid gneiss sheets, quartz-magnetite rocks (banded iron-formation s.l.) and quartz-biotite schists within amphibolitized rocks of basaltic affinity with local retrogressions. If the various Inukjuak supracrustal belts were once a part of a larger coherent (now dismembered) terrane, they should show similar emplacement ages and source chemistry. New zircon Usingle bondPb geochronology from five gneissic units and two quartz-biotite (metasedimentary) schists reveal the oldest emplacement ages across all units of each individual rock type to be 3.68 ± 0.07 Ga (granitoid gneisses) and 3.65 ± 0.06 Ga (quartz-biotite schists). These new ages are similar to those documented as likely minimum emplacement ages of the NSB determined by Usingle bondPb geochronology. Zircons from the quartz-biotite schist were also analyzed by ion microprobe for their Usingle bondPb geochronology and were found to yield statistically identical, albeit more precise, ages than those obtained by LA-ICP-MS. Possible detrital zircons from the USB quartz-biotite schists were analyzed by ion microprobe for their coupled δ30SiNBS28 ...