Nikolay A. Gongurov, State enterprise Polar Marine Geosurvey Expedition (PMGRE), 24 st. Pobedy, Lomonosov, Saint-Petersburg, 189510, Saint Petersburg, Russia, Anatoly A. Laiba, PMGRE, Saint-Petersburg, Russia, and Boris V. Belyatsky, Antarctic geology, Institute for Geology and Mineral Resources of the World Ocean (VNIIOkeangeologia), Angliiskiy ave., 1, St.Petersburg, 190121, Russia.
Precambrian rocks at Mt Meredith underwent granulite-facies metamorphism M1. Zircon isotope dating for two orthogneisses revealed the following age signatures: 1294±3 and 957±4Ma; 1105±5 and 887±2Ma. The oldest ages could reflect the time of orthogneiss protolith crystallization and the latest age determinations date Grenvillian metamorphism. The metamorphic rocks were intruded by two-mica and garnet-biotite granites. The granites and host rocks underwent amphibolite-facies metamorphism M2. Zircon isotope analysis of the two-mica granites showed age estimation within 550-510Ma and zircon dating of the garnet-biotite granites revealed the ages of 1107±5, 953±8, and 551±4Ma. As Pan-African age signatures were obtained from only the granite samples, it is possible to suggest that the granites were formed at the time of 510-550Ma and the zircons with greater age values were captured by granites from the host rocks.
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