Thursday, 30 August 2007
4.PS-104
Mafic dykes in the southern Prince Charles Mountains: A tale of Pan-African amalgamation of East Antarctica questioned
Evgeny V. Mikhalsky, VNIIOkeangeologia, Angliisky str., 1, St.-Petersburg, 190121, Russia, F. Henjes-Kunst, Bundesanstalt für Geowissenschaften und Rohstoffe, Stilleweg, 2, Hannover, 30655, Germany, B.V. Belyatsky, Department of Antarctic Geology, VNIIOkeangeologia, Angliisky str., 1, St.-Petersburg, Russia, and N.W. Roland, Bundesanstalt fur Geowissenschaften und Rohstoffe, Stilleweg, 2, Hannover, 30655, Germany.
We present new geochemical and U–Pb zircon data on mafic dykes from the southern Prince Charles Mountains Enderby Land and the Vestfold Hills. Abundant younger dykes are variously enriched in the LILE and comprise low- and high-LILE geochemical groups, as do the dykes in the abovementioned areas. The dykes in the southern Prince Charles Mountains are roughly co-eval and compositionally identical to those reported from the Enderby Land and the Vestfold Hills and were derived from the same or quite similar mantle source(s). This suggests that these parts of East Antarctica were conjugated and behaved as a single continental landmass since the early Palaeoprotrozoic and questions a widely accepted model of Pan-African amalgamation of these blocks.