Superposition of Neoarchean and Paleoproterozoic tectonics in the Terre Adélie Craton (East Antarctica): evidence from Th-U-Pb ages on
Summary In order to emphasize the tectonic behaviour of stabilized continental crust during later 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...
| Other Authors: | |
|---|---|
| Format: | Text |
| Language: | English |
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.529.3150 http://pubs.usgs.gov/of/2007/1047/ea/of2007-1047ea072.pdf |
| Summary: | Summary In order to emphasize the tectonic behaviour of stabilized continental crust during later 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 |
|---|