Superimposed Neoarchaean and Paleoproterozoic tectonics in the Terre Adelie Craton (East Antarctica): Evidence from Th-U-Pb ages on monazite and Ar-40/Ar-39 ages

• Published in: Precambrian Research
• Main Authors: Duclaux, G., Rolland, Yan, Ruffet, Gilles, Ménot, René-Pierre, Guillot, S., Peucat, Jean-Jacques, Al., Et
• Other Authors: Laboratoire Magmas et Volcans (LMV), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Géoazur (GEOAZUR 6526), Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UniCA)-Université Côte d'Azur (UniCA)-Centre National de la Recherche Scientifique (CNRS), Géosciences Rennes (GR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre Armoricain de Recherches en Environnement-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géodynamique des Chaines Alpines (LGCA), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2008
• Subjects: [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry; [SDE.MCG]Environmental Sciences/Global Changes; [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics; Antarc*; Antarctica; East Antarctica
• Online Access: https://insu.hal.science/insu-00352921; https://doi.org/10.1016/j.precamres.2008.09.009

International audience In order to understand the tectonic behaviour of a stabilized Neoarchaean continental crust during subsequent tectonic activity,we investigated the compositemetamorphic basement along the Terre Adélie and George Vth Land coastline, also known as the Terre Adélie Craton (East Antarctica). Two domains are recognized: (1) a Neoarchaean basement, composed of granulite rocks to the east and overlain to thewest by amphibolites, and (2)two Paleoproterozoic detrital basins overly theNeoarchaean crust and extend further west.Newgeochronological data fromthe Terre Adélie Craton define a tectonic evolution with threemajor peaks' activity. Th­U­Pb electron probe analyses of monazite from the Neoarchaean granulites constrain the main structuration event at ca. 2.45 Ga in agreement with zircon ages from throughout the Neoarchaean domain. Local resetting together with low temperature recrystallization of monazites occurred at ca. 1.7Ga along hydrated anastomozing metre-scale shear zones. New 40Ar/39Ar ages obtained by stepwise heating techniques on amphibole, biotite and muscovite from both the Neoarchaean basement and the Paleoproterozoic basins, illustrate the differential evolutions of basement and its sedimentary cover during the major 1.7Ga transpressive event. A final event at ca. 1.55­1.50 Ga is only recognized close to the Mertz Shear Zone (145.E) bounding the Terre Adélie Craton to the East. The new data allow us to propose detailed geological pictures of the Terre Adélie Craton geodynamic evolution, from the Neoarchaean to the Mesoproterozoic.