Time resolution of metamorphic-magmatic events in the Palaeozoic active margin of the northern Wilson Terrane (Ross Orogen, North Victoria Land)

The Wilson Terrane in North Victoria Land (Antarctica) belongs to the Early-Palaeozoic Ross Accretionary Orogen. High-grade metamorphism and magmatism of the Granite Harbour Intrusives are attributed to a magmatic arc setting of the terrane. U-Pb zircon/monazite as well as K-Ar and Ar-Ar mica/hornblende age data is yet available from the Oates Coast to the north. It signalize a ~490-470 Ma rapid cooling subsequent to isothermal decompression during granulite-facies conditions, apparently untypical for a magmatic arc evolution.

A better understanding of these observations can be expected by an extensive screening of metamorphic and magmatic ages in the Wilson Hills, the Lazarev Mountains and the Daniels Range by the electron-microprobe (EMP) monazite dating method on numerous samples recovered during the GANOVEX expedions. The cost and time-efficient EMP monazite dating and related metamorphic studies potentially can provide information on (a) pre-Ross orogenic thermal events, (b) P-T-time evolution by correlation of mineral-chemical data from monazite and garnet-bearing assemblages, (c) protolith ages on acidic members of the Granite Harbour Intrusives suite and (d) ages of the major thrusting events. The study contributes in an exemplaric way to resolve the geodynamic processes in a magmatic arc terrane which is a characteristic part of an Early-Palaeozoic accretionary orogen.



Fig. 1. Sketch map of the research area. Positions of the main thrusts after Flöttmann and Kleinschmidt (1991, 1993; LMW: Lazarev Mountains western thrust, E: Exiles Thrust, W: Wilson Thrust) and locations mentioned in the text.

Scientists

Uli Schüssler
Lehrstuhl für Geodynamik und Geomaterialforschung
Universität Würzburg

Bernhard Schulz
Mineralogisches Institut TU Bergakademie Freiberg

Research areas

Publications

Schulz B, Schüssler U, Henjes-Kunst F, 2010. Evaluation of EMP-Th-U-Pb monazite ages and comparison to U-Pb SHRIMP data in the high-grade Wilson Terrane (Antarctica). Abstracts 88. Jahrestagung der Deutschen Mineralogischen Gesellschaft in Münster, S. 206.

Homepage

---

Research funding organisation

German Research Foundation

Project number: Schu 873/6-1
Funding period: Since 2008