Thursday, 30 August 2007 - 1:30 PM
4.P1.C-1
Superposition of Neoarchean and Paleoproterozoic tectonics in the Terre Adélie Craton (East Antarctica): evidence from Th-U-Pb ages on monazite and Ar-Ar ages
Guillaume Duclaux1, Yann Rolland2, Gilles Ruffet3, René-Pierre Ménot4, Stéphane Guillot5, Jean Jacques Peucat3, C.M. Fanning6, and Arnaud Pécher5. (1) UMR CNRS 6524 "Magmas et Volacans" and EarthByte Group (Sydney Univeristy), University Jean Monnet, Saint Etienne, Saint Etienne, 42023, France, (2) UMR CNRS 6526, Geosciences Azur, University of Nice, Sophia-Antipolis, France, (3) UMR CNRS 6118, Geoscience Rennes, University of Rennes 1, Rennes, 35042, France, (4) UMR CNRS 6524 "Magmas et Volcans", University Jean Monnet, Saint Etienne, 23 rue Dr Paul Michelon, F-42023 - Saint Etienne, France, (5) UMR CNRS 5025, Laboratoire de Géodynamique des Chaînes Alpines, University Joseph Fourier, Grenoble, France, (6) Research School of Earth Sciences, Australian National University, Canberra, ACT 2000, Australia
In order to emphasize the tectonic behaviour of stabilized continental crust during latter tectonic activity, we investigated the composite metamorphic basement of the Terre Adélie Craton (TAC). Two domains are recognized: (1) a Neoarchean basement, made of a deep granulitic crust to the East, and an amphibolitic crust to the West, and (2) two Paleoproterozoic basins overlying the Neoarchean amphibolitic crust and extending further West. New geochronological data from the TAC reveal a tectonic evolution with two major events. Monazites ages from the Neoarchean granulitic crust illustrate a main tectono-metamorphic event around 2.45Ga. Localized resetting of monazites geochronometer occurred around 1.7Ga within small fluid bearing shear zones. New 40Ar/39Ar ages from amphibole, and micas from both Neoarchean basement and Paleoproterozoic basins illustrate their differential evolution during a major 1.69Ga event. Finally, 1.55-1.5Ga ages are only recognized close to the Mertz Shear Zone along the Eastern craton boundary.
See more of Evolution of antarctic lithosphere ORAL
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See more of The 10th International Symposium on Antarctic Earth Sciences (Aug. 26 to Sept 1, 2007)
See more of General Submissions
See more of The 10th International Symposium on Antarctic Earth Sciences (Aug. 26 to Sept 1, 2007)