Geological studies in the Baalsrudfjellet nunatak between the Schirmacher Oasis and the Wohlthat Mountains to establish the continuation of the East African Orogen (EAO) in central Dronning Maud Land, East Antarctica
S. K. Roy, N. C. Pant, A. Kundu, A. Dharwadkar, P. K. Kumar, Sonalika Joshi, Raghuram, Mohd. Sadiq, Mayuri Pandey, 2017. "Geological studies in the Baalsrudfjellet nunatak between the Schirmacher Oasis and the Wohlthat Mountains to establish the continuation of the East African Orogen (EAO) in central Dronning Maud Land, East Antarctica", Crustal Evolution of India and Antarctica: The Supercontinent Connection, N. C. Pant, S. Dasgupta
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The 600–660 Ma East African Orogen (EAO) granulites of the Mozambique Belt were correlated and extended into a coast marginal area of East Antarctica through the NNW–SSW-trending granulite-bearing Schirmacher Oasis. Tracing similarities in lithological association, granulite-facies metamorphism and geochronological data, the 640 Ma EAO was extended by another 110 km south of Schirmacher into the Humboldt Mountains in central Dronning Maud Land (cDML). Based on younger anorogenic magmatism east and west of the Humboldt Mountains, a 10–20 km-wide linear corridor of the EAO from the Schirmacher to the Humboldt Mountains was proposed.
There are eight nunataks between Schirmacher and the Humboldt Mountains projected above the ice sheet. These nunataks are strategically placed because they represent the small (4–10 km2), isolated rock exposures in approximately 5000 km2 of ice-covered area. Baalsrudfjellet is one of these nunataks that is located at the easternmost margin of the proposed EAO corridor and represents a significant outcrop to validate the presence of the EAO between Schirmacher and the Humboldt Mountains. This study brings out a two-stage metamorphic evolution (c. 660–680 Ma and c. 580 Ma) with melt generation associated with the younger event. Geochronological constraints by monazite chemical dating from metapelites confirm and validate the continuation of the EAO in-between the Schirmacher Oasis and the Humboldt Mountains.
Supplementary material: Monazite analyses, computed ages and age errors of three grains from the high- and low-melt metapelite are available at https://doi.org/10.6084/m9.figshare.c.3738362