Regional metamorphism and P-T evolution of the Ross Orogen in northern Victoria Land (Antarctica): a review

The main focus of this paper is on the petrological evolution of medium- to high-grade metamorphic units in the Wilson Terrane, the westernmost lithotectonic unit of the Ross Orogen in northern Victoria Land. The petrological data set is reviewed for all areas where P-T-t paths have been reconstructed and geochronological data are sufficiently complete to provide an overview of the regional metamorphic evolution of a ca. 600 km long segment of the Ross Orogen, from its termination along the Pacific coast to the Eisenhower Range near the Ross Sea coast. Petrological evidence reveals that different lithological units of the Wilson Terrane equate with distinct lithotectonic metamorphic complexes with partly independent P-T-t histories. In spite of the wide range of estimated peak metamorphic conditions, and variability in both shape of the P-T path (clockwise or counter-clockwise) and type of retrograde evolution (isobaric cooling or cooling/unloading), the reviewed P-T-t trajectories consistently support a setting of evolving subduction and accretion in the context of a Palaeozoic cordilleran-type active margin.