Timing of Grenville-age vs. Pan-African medium- to high grade metamorphism in western Dronning Maud Land (East Antarctica) and significance for correlations in Rodinia and Gondwana
摘要
Heimefrontfjella in western Dronning Maud Land, East Antarctica, is part of the c. 1.1Ga Namaqua–Natal–Maud Belt. It is situated at an important location, both for Rodinia reconstructions and at the western orogenic front of the Late Neoproterozoic/Early Palaeozoic East African/Antarctic Orogen. Six basement samples help to precisely date the Grenville-age metamorphism between c. 1090 and 1060Ma. These dates indicate that palaeomagnetic data from the Coats Land Block to the south of the Maud Belt cannot be taken to support the contiguity of the Coats Land/Maud/Grunehogna continental fragment and Kalahari during Late Mesoproterozoic times. A comparison of aeromagnetic data and crustal provinces indicates that the Coats Land basement is likely to be composed of pre-Mesoproterozoic basement that was differentially reworked at c. 500Ma within the East African/Antarctic Orogen.