Pan-African intraplate deformation in the northern Prince Charles Mountains, east Antarctica

New structural and metamorphic data coupled with U-Pb SHRIMP zircon and Rb-Sr step-leach biotite ages help constrain a period of Early Palaeozoic (Pan-African) deformation recognised in the northern Prince Charles Mountains, east Antarctica. This period of deformation is accommodated along discrete...

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Bibliographic Details
Published in:Earth and Planetary Science Letters
Main Authors: Boger, Steven D., Carson, Christopher J, Fanning, Christopher, Hergt, Janet, Wilson, Colin J, Woodhead, Jonathan
Format: Article in Journal/Newspaper
Language:unknown
Published: Elsevier
Subjects:
Keywords: continental collision
crustal deformation
geochronology
Gondwana
intraplate process
mylonite
Pan African orogeny
Antarctica Geochronology
Godwana
Pan-African Orogeny
Prince Charles Mountains
Rb/Sr
SHRIMP data
East Antarctica
Prydz Bay
Lützow-Holm Bay
Antarc*
Antarctica
Online Access:http://hdl.handle.net/1885/92565
https://doi.org/10.1016/S0012-821X(01)00587-8
https://openresearch-repository.anu.edu.au/bitstream/1885/92565/5/MigratedxPub23688_RSD_2002.pdf.jpg
https://openresearch-repository.anu.edu.au/bitstream/1885/92565/7/01_Boger_Pan-African_intraplate_2002.pdf.jpg
Description
Summary:New structural and metamorphic data coupled with U-Pb SHRIMP zircon and Rb-Sr step-leach biotite ages help constrain a period of Early Palaeozoic (Pan-African) deformation recognised in the northern Prince Charles Mountains, east Antarctica. This period of deformation is accommodated along discrete northeast trending mylonites that preserve up-dip reverse kinematics with dominantly southeast over northwest vergence. Ambient P-T conditions of 524 ± 20°C and 7.6 ± 4 kbar accompanied deformation. This phase of deformation post-dated the intrusion of planar felsic dykes that yield ages of c. 550 Ma and pre-dated Rb-Sr biotite ages of c. 475 Ma that record cooling of the terrane below c. 300°C. These mylonites are identical in age to continental collisional events recognised in the southern Prince Charles Mountains and Prydz Bay, which lie to the south and east of the northern Prince Charles Mountains, and similar in age to orogenesis recognised to the west in Lützow-Holm Bay. These belts represent sutures between the component lithospheric blocks of east and west Gondwana. The northern Prince Charles Mountains lie between these sutures. Consequently, the mylonites we report here are interpreted to have formed in an intraplate setting and developed in response to stresses applied along the plated margins as a consequence of continental collision during the amalgamation of Gondwana.

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