Déformations tardi-grenvilliennes dans la ceinture parautochtone (Province de Grenville centrale) : contraintes géochronologiques par couplage de méthodes U–Pb de haute résolution spatiale et de haute précision

Petrogenesis of LREE-rich pegmatitic granite dykes in the central Grenville Province by partial melting of Paleoproterozoic-Archean metasedimentary rocks: Evidence from zircon U-Pb-Hf-O isotope and trace element analyses

“…815-850 °C (Hynes et al, 2000;Jannin et al, 2018a;Jordan et al, 2006;Rivers, 2009;Rivers et al, 2012;van Gool et al, 2008). These conditions were documented in the Knob Lake Group that unconformably overlie the Laurentian basement (Fig.…”

“…These conditions were documented in the Knob Lake Group that unconformably overlie the Laurentian basement (Fig. 2, Gagnon Terrane, Hynes et al, 2000;Rivers, 1980;Rivers et al, 1989 (Jannin et al, 2018a;Jordan et al, 2006). Partial melting of these metasediments as early as ca.…”

“…1002 Ma is documented by U-Pb dating of metamorphic rims of zircon grains, which exhibit HREE-depletion and absence of negative Eu anomalies, indicating their growth in presence of peritectic garnet with no plagioclase (Jannin et al, 2018a). The retrograde P-T path occurred in the sillimanite stability field between 995 and 985 Ma as monazite crystallized in melt (Jordan et al, 2006) and most probably lasted until ca.…”

“…961 Ma, as indicated by synkinematic intrusion of dykes and sills of pegmatite on the southern shore of the Manicouagan Reservoir at upper and lower structural levels of the Parautochthonous and Allochthonous belts, respectively (Fig. 2, Jannin et al, 2018a). A recent reappraisal of the structural and geochronological data of the ABT showed that the down-to-the-SE Thachic shear zone (TSZ, Fig.…”

“…Rivers, 2008) with abundant evidence of partial melting (e.g. Indares et al, 2008;Jannin et al, 2018a;Slagstad et al, 2004;Timmermann et al, 2002;Turlin et al, 2018) and mafic magmatism (Rivers and Corrigan, 2000). Accordingly, this province represents a potential target to test these hypotheses.…”