| Abstract: | A review of numerous isotopic-geochronological studies is given. The major attention is paid to modern U-Pb zircon measurements using the SHRIMP method. The major tectogenesis stages recognized in the Antarctic shield are Archean (3800–3300, 3100–2800, and 2550–2450 Ma), Paleoproterozoic (2200–2000 and 1850–1700 Ma), Mesoproterozoic (1400–1250 and 1200–920 Ma), and Neoproterozoic-Early Paleozoic (600–500 Ma). Ancient Eo-and Paleoarchean processes (intrusion of tonalite gneisses protoliths, or metamorphism) took place at Enderby Land, Kemp Land, and the Prince Charles Mountains. At some localities tectonic activity ended at 1700 Ma, at other places reworking or rejuvenation occurred later. Mesoproterozoic tectogenesis was not synchronous. The completion phases of tectonic activity are known to have occurred in different places 1150, 1050, and 980–920 Ma ago. In areas of Mesoproterozoic tectogenesis, evidence of Paleoproterozoic or (rarely) Archean endogene processes is sometimes found. Most likely, this stage refers to the formation of the vast continental block. The Neoproterozoic-Early Paleozoic tectogenesis was practically synchronous over most of the Antarctic shield; on large areas it was characterized by metamorphism and pervasive schistosity, but in many other localities only various granitoids and pegmatites were intruded. Within all the areas of Neoproterozoic-Early Paleozoic tectogenesis isotopic evidence of the earlier (largely Mesoproterozoic) endogene processes are found. |
