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

北维多利亚陆威尔逊地体属于早古生代罗斯增生造山带。花岗岩港湾侵入体的高级变质作用和岩浆作用归因于岩浆弧环境。U-Pb锆石/独居石以及KAr和Ar-Ar云母/角闪石年龄数据从奥茨海岸北部。它标志着一个~490 - 470 Ma的快速冷却后，等温减压麻粒岩相条件下，显然不典型的岩浆弧演化。通过对GANOVEX考察期间回收的大量样品进行电子微探针独居石测年，对威尔逊山、拉扎列夫山和丹尼尔斯山脉的变质和岩浆年龄进行广泛筛选，可以更好地了解这些观测结果。EMP独居石测年和相关变质研究的成本和时间效率可能提供以下信息：（a）前罗斯造山热事件，（B）P-T-时间演化的相关矿物化学数据从独居石和石榴子石组合，（c）花岗岩港侵入岩套酸性成员的原岩年龄和（d）主要逆冲事件的年龄。该研究为解决早古生代增生造山带中岩浆弧的地球动力学过程提供了一个范例。

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 KAr 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 granulitefacies 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.