The formation of Neoarchean continental crust in the south-east Superior Craton by two distinct geodynamic processes

Mole, David R.; Thurston, P. C.; Benowitz, Jeffrey A.; Stern, Richard A.; Ayer, J. A.; Martin, Laure; Lu, Yongjun

doi:10.1016/j.precamres.2021.106104

Cited by 66 publications

(13 citation statements)

References 155 publications

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“…(a) It is likely that the S1 feature is caused by the delamination and sinking of the lower crust into the mantle and the middle crust dimmed reflection zones, M1 and M2, were caused by intrusions from the partial melting of the S1 feature. This interpretation is compatible with the finding of a recent geochemical study that portraits a continental‐rift setting, driven by early plume magmatism in the central Abitibi (Mole et al., 2021). (b) It could also represent a deeper segment of the PDF that was preserved below the Moho.…”

Section: Discussionsupporting

confidence: 91%

Active and Passive Seismic Imaging of the Central Abitibi Greenstone Belt, Larder Lake, Ontario

et al. 2022

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The seismic reflection method is considered to be one of the most accurate depth-resolving geophysical prospecting methods. A man-made/active source of seismic energy, vibroseis or explosives, propagates into the subsurface and the reflected seismic energy is recorded by an array of geophones. The collected data are then processed to generate a section that gives an indication of the subsurface acoustic impedance variations. The ME321-R1 seismic reflection transect, acquired as part of the Metal Earth project in 2017, is an ∼44-km long north-south transect that covers the Larder Lake area. Previously, the Lithoprobe project (Clowes et al., 1992) also acquired several reflection seismic profiles in the central Abitibi area in close proximity to the Larder Lake area (Ludden & Hynes, 2000). Together, these transects can provide vital information about the reflectivity structure and tectonic evolution of the central Abitibi.

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Section: Discussionsupporting

confidence: 91%

Active and Passive Seismic Imaging of the Central Abitibi Greenstone Belt, Larder Lake, Ontario

et al. 2022

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“…The geodynamic evolution of the Archean crust, including the Abitibi Subprovince, remains controversial. The main geodynamic models include: (1) subduction and accretion of associated volcanic arcs Ludden and Hubert 1986;Kimura et al 1993;Calvert et al 1995;Calvert and Ludden 1999;Wyman et al 2002), as was suggested for the Chibougamau area D r a f t (Polat et al 2018); (2) mantle plume-driven crustal reworking activity with associated arc-type volcanism (Rey et al 2003;Gerya et al 2015), which could be followed by subduction (Ayer et al 2002;Wyman et al 2002); (3) delamination, including aspects of a subcretion model, implying horizontal movements followed by the imbrication of a crust that is too thick to subduct (Bédard et al 2003;Bédard et al 2013;Bédard 2018) and; (4) rifting of a cratonic nucleus (Mathieu et al 2020b;Mole et al 2021), to produce a 30-40 km thick mafic crust by the partial melting of a hot ambient mantle (Herzberg et al 2010); however, the study of Roman and Arndt (2020) show that such a process is not plausible on Earth. Hypothetical models (3) and ( 4) consider that partial melting occurred at the base of the thickened crust (Van Kranendonk et al 2015).…”

Section: Résumémentioning

confidence: 94%

Petrogenesis and mode of emplacement of a Neoarchean tonalite–trondhjemite–diorite suite: the Eau Jaune Complex, Abitibi greenstone belt

et al. 2022

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Magmatism during the maturation phase of Archean greenstone belts produced voluminous tonalite-trondhjemite-granodiorite (TTG) suites, as well as a lesser amount of tonalite-trondhjemite-diorite (TTD) suites. Such TTD suites have recently been recognized in the Archean Abitibi greenstone belt, on the southern flank of the Superior Craton, Canada, but their source(s), differentiation processes and depths of emplacement remain poorly constrained. The Neoarchean Eau Jaune Complex (EJC) lies in the northeastern corner of the Abitibi greenstone belt and represents one of the most voluminous tonalite-dominated and diorite-bearing intrusive suites of the Chibougamau region. This TTD suite comprises six intrusive phases with distinct petrology and chemistry. All units were emplaced as laccolith-like intrusions injected along discontinuities within the volcanic succession at ca. 2724 Ma (U-Pb zircon dating), during the synvolcanic interval (i.e., construction and maturation phase), at a depth of approximately 7–8 km. The most HREE-depleted phases (granodiorite, tonalite and trondhjemite) correspond to magmas that fractionated amphibole and were likely produced by partial melting of a garnet- and titanate-bearing amphibolite, akin to TTG magmas. The least HREE-depleted phases are dioritic in composition and correspond to mantle-derived magmas that may have interacted with TTG melts. This indicates interaction between coeval mantle-derived and crustal melts during the maturation phase of the Abitibi greenstone belt. Models formulated to address the geodynamic evolution of greenstone belts must account for the coeval production of basalt-derived (TTG suites) and mantle-derived (tholeiitic magmatism) melts occasionally interacting to form TTD suites.

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“…Arc-like geochemical signatures are common in the Abitibi (Ayer et al, 2002) but do not prove that volcanic arcs and subduction zones existed, as there could have been a number of different ways to produce the observed signatures (Pearce, 2008;Bédard et al, 2013;Mole et al, 2021). Because Archean rocks are not as depleted as modern volcanic rocks, many argue that modern plate tectonic processes could not have been the cause of negative Nb-Ta anomalies and high Th concentrations (Bédard et al, 2013;Thurston, 2015).…”

Section: Comparison With Archean Felsic Volcanic Rocksmentioning

confidence: 99%

“…Because Archean rocks are not as depleted as modern volcanic rocks, many argue that modern plate tectonic processes could not have been the cause of negative Nb-Ta anomalies and high Th concentrations (Bédard et al, 2013;Thurston, 2015). A number of alternative models of Archean greenstone belt evolution have been suggested that could account for the differences (e.g., dome-and-keel and mantle wind models: Sawyer et al, 1994;Bédard et al, 2013;Thurston, 2015;Mole et al, 2021). Some have suggested that crustal contamination created the arc-like signatures, which is consistent with the Th enrichment identified in the random forest classification and with evidence of older crust beneath the Abitibi greenstone belt (e.g., Mole et al, 2021).…”

Section: Comparison With Archean Felsic Volcanic Rocksmentioning

confidence: 99%

Geochemical Signatures of Felsic Volcanic Rocks in Modern Oceanic Settings and Implications for Archean Greenstone Belts

et al. 2023

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Felsic volcanic rocks are abundant in ancient greenstone belts and important host rocks for volcanogenic massive sulfide (VMS) deposits. About half of all VMS deposits are hosted by dacite or rhyolite, an association that reflects anomalous heat flow during rifting, partial melting of basaltic crust, and fractional crystallization in high-level magma chambers. For over 30 years, geochemical signatures of these rocks (e.g., F classification of Archean rhyolites) have been widely used to identify possible hosts for VMS deposits in ancient greenstone belts. However, comparisons with modern oceanic settings have been limited, owing to a lack of samples of felsic volcanic rocks from the sea floor. This is changing with increasing exploration of the oceans. In this study, we have compiled high-quality geochemical analyses of more than 2,200 unique samples of submarine felsic volcanic rocks (>60 wt % SiO2) from a wide range of settings, including mid-ocean ridges, ridge-hot-spot intersections, intraoceanic arc and back-arc spreading centers, and ocean islands. The compiled data show significant geochemical diversity spanning the full range of compositions of rhyolites found in ancient greenstone belts. This diversity is interpreted to reflect variations in crustal thickness, the presence or absence of slab-derived fluids (dry melting versus wet melting), and mantle anomalies. Highly variable melting conditions are thought to be related to short-lived microplate domains, such as those caused by diffuse spreading and multiple overlapping spreading centers. Systematic differences in the compositions of felsic volcanic rocks in the modern oceanic settings are revealed by a combination of principal components analysis, unsupervised hierarchical clustering, and supervised random forest classification of the compiled data. Dacites and rhyolites from midocean ridge settings have moderately depleted mantle signatures, whereas rocks from ridge-hot-spot intersections and ocean islands reflect enriched mantle sources. Felsic volcanic rocks from arc-back-arc systems have strongly depleted mantle signatures and well-known subduction-related chemistry (strong large ion lithophile element enrichment in combination with strong negative Nb-Ta anomalies and low heavy rare earth elements [HREEs]). This contrasts with felsic volcanic rocks in Archean greenstone belts, which show high field strength element and HREE enrichment (so-called FIIIb-type) due to a less depleted mantle, a lack of wet melting, and variable crustal contamination. The differences between modern and ancient volcanic rocks are interpreted to reflect the lower mantle temperatures, thinner crust, and subduction-related processes in present-day settings. We suggest that the abundance of FIIIb-type felsic volcanic rocks in Archean greenstone belts is related to buoyant microplate domains with thickened oceanic crust that were better preserved on emerging Archean cratons, whereas in post-Archean tectonic settings most of these rocks are subducted.

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The formation of Neoarchean continental crust in the south-east Superior Craton by two distinct geodynamic processes

Cited by 66 publications

References 155 publications

Active and Passive Seismic Imaging of the Central Abitibi Greenstone Belt, Larder Lake, Ontario

Active and Passive Seismic Imaging of the Central Abitibi Greenstone Belt, Larder Lake, Ontario

Petrogenesis and mode of emplacement of a Neoarchean tonalite–trondhjemite–diorite suite: the Eau Jaune Complex, Abitibi greenstone belt

Geochemical Signatures of Felsic Volcanic Rocks in Modern Oceanic Settings and Implications for Archean Greenstone Belts

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