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), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne 2017-2020 (UCA 2017-2020 )-Centre National de la Recherche Scientifique (CNRS), 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://uca.hal.science/hal-03101296; https://uca.hal.science/hal-03101296/document; https://uca.hal.science/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 ...