U-Pb ages (3.8–2.7 Ga) and Nd isotope data from the newly identified Eoarchean Nuvvuagittuq supracrustal belt, Superior Craton, Canada

Atmospheric record in the Hadean Eon from multiple sulfur isotope measurements in Nuvvuagittuq Greenstone Belt (Nunavik, Quebec)

“…S1) (17)(18)(19)(20)]. These age relationships are consistent with the inferred intrusive relationships among the throndhjemite bands, the gabbro sills, and the amphibolite (15).…”

Protocrustal evolution of the Nuvvuagittuq Supracrustal Belt as determined by high precision zircon Lu–Hf and U–Pb isotope data

“…Rizo et al, 2011). To shed light on this discussion and test models for the presence or absence of Hadean crust in the NSB or in the source to the NSB felsic rocks, we here present new high precision U-Pb isotope dilution thermal ionisation mass spectrometry (ID-TIMS) and coupled Lu-Hf solution inductively coupled plasma mass spectrometry (S-MC-ICPMS) data from two felsic gneisses originally dated by David et al (2009). The new data from a felsic schist (1091F) interpreted to be an extrusive volcanic rock (David et al, 2009), provide precise age constraints on the formation of the NSB.…”

“…The Nuvvuagittuq Supracrustal Belt (NSB) is one of a few known Eoarchean or older crustal fragments preserved in the Earth's crust (Cates and Mojzsis, 2007;O'Neil et al, 2008;David et al, 2009). These crustal fragments provide unique possibilities to study the evolution of the early Earth and to gain insights into processes that were active during their formation, as for example whether subduction processes were involved in the formation of felsic rocks already in the Eoarchean (e.g.…”

“…Crucial to the study of these rock complexes is knowing their timing of formation, specifically their crystallisation and crustal evolution, and the timing and nature of mantle extraction, differentiation and evolution. As the NSB is highly deformed (as is generally the case for Eoarchean rock complexes) and has gone through several cycles of high grade metamorphism (Cates and Mojzsis, 2007;David et al, 2009), obtaining robust and unambiguous geochronological and isotopic information unravelling the different aspects of its evolution have presented a challenge. In recent years there has been a debate on whether (some of) the gneisses of the NSB were actually crystallised in and incorporated into the crust in the Early Hadean (O'Neil et al, 2008 or whether these rocks were formed in the Eoarchean (Cates and Mojzsis, 2007;Cates et al, 2013;Guitreau et al, 2013) and rather sampled an enriched mantle source that had differentiated in the early Hadean as has been suggested for example for the Isua Supracrustal Belt (e.g.…”

The discovery of the Earth's oldest rocks

“…Rocks very similar in character, age and extent to the Isua region rocks discussed in this paper have recently been reported from an area east of Hudson Bay in Canada. 26 The discovery of the Earth's oldest rocks isotopic and mineralogical information on the previous 700 Myr of Earth history, from which no bulk rocks survive.…”