Structure and metamorphism of the Antarctic Shield

Autor: R. G. Kurinin, V. A. Maslov, S. V. Semenov, V. S. Semenov, E. N. Kamenev, N. L. Alekseev, I. A. Kamenev, V. M. Mikhailov
Rok vydání: 2013
Předmět:
Zdroj: Geotectonics. 47:115-130
ISSN: 1556-1976
0016-8521
DOI: 10.1134/s0016852113020027
Popis: The information on the composition, structure, P-T conditions of metamorphic facies, evolution, and time of the metamorphic events in the largest Precambrian tectonic provinces of the Antarctic Crystalline Shield gained over more than a half-century is summarized in this paper. The joining up of the ortho- and paracrystalline rocks into complexes and groups according to their geographic position, composition, age, and the character of their metamorphism allowed us to consider the main features of the structure and evolution of the provinces including (1) the near-latitudinal polycyclic Late Precambrian-Early Paleozoic Wegener-Mawson Mobile Belt, extended for more than 4000 km, which started to evolve in the Mesoproterozoic and stabilized only at the end of Cambrian; (2) the Early Precambrian relict crystalline protocratonic blocks adjoining this mobile belt; their history is traced from the Eoarchean; and (3) the near-latitudinal Late Precambrian-Early Paleozoic aulacogen in the southern protocratonic block. The P-T conditions of the metamorphism from the pyroxene-granulite subfacies in the protocratonic blocks to the greenschist facies in aulacogen, as well as the age of the magmatic and metamorphic events in all the tectonic provinces of the shield, are characterized. This made it possible to consider the metamorphic history and conditions of the continental crust’s formation in Antarctica, where the oldest crystalline rocks are dated to the Eoarchean (4060–3850 Ma) and the youngest rocks are ∼500 Ma old.
Databáze: OpenAIRE
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