Thermochronological (Ar-40/Ar-39) evidence of Early Palaeozoic basin inversion within the southern Prince Charles Mountains, East Antarctica: Implications for East Gondwana

Abstract

40Ar/39Ar systematics within metasedimentary rocks exposed in the southern Prince Charles Mountains, East Antarctica, were thermally reset during a period of Early Palaeozoic (between 524 ± 1 Ma and 486 ± 2 Ma) orogenesis. This event affected three temporally distinct (Archaean to Neoproterozoic) stratigraphic levels that are now exposed in the upper crust. In the structural record, evidence of orogenesis during Early Palaeozoic times is preserved as late-stage, subvertical mylonite zones in the Archaean orthogneiss-metasedimentary basement and thin-skinned folding and thrusting of the overlying Neoproterozoic metasedimentary rocks. Synchronous cooling ages, contrasting structural styles and..