Crustal reworking and Eo-Paleoarchean metamorphism of the northern Pikwitonei domain, Superior Province: U-Pb-Hf-TE analysis of 3.9–3.2 Ga detrital zircon
U-Pb-Lu-Hf-trace element analysis of detrital zircon from two metasedimentary rocks of the Armstrong assemblage in the northern Pikwitonei granulite domain of the NW Superior Province (Manitoba, Canada) are used to explore the Eo-Paleoarchean crustal formation history and zircon petrogenetic processes of the proto-Superior craton. The zircon age spectrum from each sample spans a billion-year period from 3.85 to 2.65 Ga, with a predominant 3.85–3.40 Ga detrital zircon age population. The ca. 3.85 Ga detrital zircon grains from each sample have subchondritic εHf(t) values between −3.9 and − 1.0, consistent with initial crystallization from a suite of late-Hadean to early-Eoarchean protoliths. Semi-continuous Eo-Paleoarchean crustal reworking is subsequently inferred based on the single uniform Hf isotope evolution trend for 3.85–3.20 Ga detrital zircon grains, which is comparable to igneous zircon populations from the Nuvvuagittuq greenstone belt on the eastern shore of Hudson Bay in Quebec. Trace element analysis of detrital zircon grains from both metasedimentary samples indicate the limited presence of detrital metamorphic zircon at 3.67 Ga, 3.5 Ga and 3.4 Ga, which reveal potential metamorphic events within the Eo-Paleoarchean Superior Province. In addition, the detrital igneous zircon grains have trace element compositions consistent with either partial melting of hydrous source rocks or magmatic reworking/assimilation of felsic rocks. The trace element compositions are broadly similar to ca. 3.9–3.2 Ga igneous zircon populations from Acasta and Saglek regions, while demonstrating the importance of calculating initial U concentrations for Hadean – Archean zircon. • Pikwitonei domain and Nuvvuagittuq belt share a similar zircon age and Hf isotope history. • Eo-Paleoarchean detrital and igneous zircon suggest intermediate-felsic crust. • Multiple episodes of crustal rejuvenation facilitated growth of the largest craton. • Archean metasedimentary rocks may contain rare detrital metamorphic zircon. • Hadean – Archean zircon TE discrimination requires initial U and Th concentrations.
Authors
- Chris G. Couëslan
- P. Thurston
- C.R.M. McFarlane
- K. Ross
- J.W.D. Strong
- Jack Simmons (ORCID: https://orcid.org/0000-0001-5168-4076)
- J. H. Marsh
Institutions
- University of New Brunswick (CA)
- Manitoba Hydro (CA)
- Laurentian University (CA)
Publication Details
- Journal
- Chemical Geology
- Published
- 2025-05-26
- DOI
- https://doi.org/10.1016/j.chemgeo.2025.122886
- Citations
- 2
- Primary Topic
- Geological and Geochemical Analysis
- Type
- article
- Field-Weighted Citation Impact
- 3.73
Funders
- Canada First Research Excellence Fund