Investigation into the Bonney pluton and other plutons of Southern Victoria Land

Previous studies suggest a large part of the Koettlitz Group deformation may be attributed to the intrusion of granitoid plutons and not solely the result of regional tectonic events as previously believed. Initial observations from the Wright Valley, with other published data from elsewhere in Southern Victoria Land attempted to derive a regional model for the intrusion of the Bonney Pluton. This data extends the study elsewhere around this pluton and into other plutons of Southern Victoria Land to create a more accurate regional model to explain plutonism and deformation in Southern Victoria Land. Fieldwork consisted of structural observations within the pluton, structural observations within the host rock metasediments and orthogneisses and geothermometry at sites in the Miers Valley. A separate study using garnet-biotite Fe-Mg exchange geothermometry was also carried out to determine temperatures of metamorphism for Koettlitz Group rocks in the Wright Valley.

过往研究表明，科特利茨群（Koettlitz Group）的变形很大程度上可归因于花岗岩质岩体（granitoid plutons）的侵入，而非此前学界认为的仅由区域构造事件单独导致。赖特谷（Wright Valley）的初始观测结果，结合南维多利亚地（Southern Victoria Land）其他区域已发表的数据，曾尝试为邦尼岩体（Bonney Pluton）的侵入作用构建区域模型。本研究将研究范围拓展至该岩体周边的其他区域以及南维多利亚地的其他岩体，以此构建更为精准的区域模型，用以阐释南维多利亚地的岩浆侵入作用与构造变形。本次野外工作涵盖岩体内部的构造观测、围岩中变质沉积岩与正片麻岩内的构造观测，以及迈尔斯谷（Miers Valley）测点的地热测温分析。另有一项独立研究采用石榴石-黑云母Fe-Mg交换地热测温法（garnet-biotite Fe-Mg exchange geothermometry，测定了赖特谷中科特利茨群岩石的变质温度。