Collaborative International Research: Investigation of Structures, Structural Fabrics and Metamorphic Associations in Northern Victoria Land

摘要该奖项允许一名美国调查员加入意大利南极计划在南极洲维多利亚地北部的地质实地小组。野外项目的总体目标是获得详细的构造、岩石学、同位素和地质年代学信息，这些信息与维多利亚地北部早古生代岩浆活动的历史有关，并将这些信息与罗斯造山运动期间的板块汇聚联系起来。该小组将验证一个假设，即NVL的高温低压变质作用发生在基本与弧相关的岩体的区域接触变质光圈内，发生在与辐合有关的结构体系内。PI的详细构造研究将有助于描述岩体形成的动态环境，并将寄主岩石中的构造结构与寄主岩石中变质再结晶的压力-温度条件的变化联系起来。该工作将用于验证岩浆弧在深部成岩作用期间的极性，并建立其与南部早古生代深部岩体的关系。这项工作的结果将用于推断南极早古生代活动边缘在NVL的配置，并与横贯南极山脉其他部分建立的模型进行比较。在这项工作中发展起来的解释将与冈瓦纳原太平洋边缘其他部分的构造和结构解释相结合。研究中使用的方法包括构造制图、构造和变质岩石学以及流体包裹体分析。美国的实地计划以深冻山脉为中心，并有可能考察兰特曼山脉附近的地点。该奖项支持的具体贡献将是研究和解释变形、岩浆脉冲和高温-低压变质再结晶之间的关系。

9702161 Siddoway Abstract This award allows a US investigator to join an Italian Antarctic Program geological field team in northern Victoria Land, Antarctica. The overall goal of the field program is to obtain detailed structural, petrographic, isotopic, and geochronological information that bears on the history of early Paleozoic magmatism in northern Victoria Land (NVL), and to relate this information to plate convergence during the Ross Orogeny. The group will test the hypothesis that high temperature-low pressure metamorphism in NVL occurred within the regional contact metamorphic aureole of fundamentally arc-related plutons, within a structural regime related to convergence. Detailed structural studies by the PI are expected to help characterize the dynamic setting in which the plutons were emplaced and correlate structural fabrics in host rock with changes in pressure- temperature conditions of metamorphic recrystallization in host rocks. The work will be used to verify the polarity of the magmatic arc during plutonism and establish the relationships with early Paleozoic plutons to the south. The results of this work will be used to infer the configuration of AntarcticaOs early Paleozoic active margin in NVL, for comparison with models developed in other parts of the Transantarctic Mountains. Interpretations developed in the course of this work will be integrated with tectonic and structural interpretations for other parts of the proto-Pacific margin of Gondwana. Methods used in the study will include structural mapping, structural and metamorphic petrology, and fluid inclusion analysis. The field program in \centered on the Deep Freeze Range, with an additional possibility of examining sites in the vicinity of the Lanterman Range. The specific contribution supported by this award will be study and interpretation of the relations between deformation, magmatic pulses, and high temperature-low pressure metamorphic recrystallization.