A Nd, Os, Pb and Sr Isotopic Study of the Dufek Intrusion, Pensacola Mountains, Antarctica: Re-assessment of Differentiation Mechanisms in Layered Mafic Complexes

该奖项支持了对杜菲克分层的同位素研究， 超镁铁质侵入体 研究的目的是 更好地理解大型镁铁质岩浆中的火成过程 准确测定杜菲克的年龄 侵入，并评估硫化物的来源， 侵入体中有铬铁矿化。 杜菲克的入侵是 Karoo-Ferrar拉斑玄武岩区的一部分， 地球上已知的省份 这项研究将涉及高 精密质谱分析钕，锶， 来自矿物超纯部分的铅和锇同位素 从岩石样本中分离出来。 这些分析将用于 液态和积云的微量成分变化 结晶过程中的（固体）相和晶体偏析 流程. 铅和锇的同位素将被用作示踪剂， 确定硫化物矿化是否是由于 与地壳污染有关的二氧化硅活动， 硫化物成矿作用仅由温度变化引起 和氧逸度。 这项研究将有助于阐明 岩浆分异成矿作用 一般都有大型超镁铁质侵入体。 这种入侵是 铂族元素的重要来源。

This award supports an isotopic study of the Dufek layered ultramafic intrusion. The objectives of the research are a better understanding of igneous processes in large mafic magma chambers, an accurate determination of the age of the Dufek intrusion, and an assessment of the origin of sulfide and chromite mineralization in the intrusion. The Dufek intrusion is part of the Karoo-Ferrar tholeiitic province, one of the largest such provinces known on Earth. This research will involve high precision mass spectrometric analysis of neodymium, strontium, lead, and osmium isotopes from ultrapure fractions of minerals separated from rock samples. These analyses will be used to trace compositional changes of both the liquid and cumulus (solid) phases during crystallization and crystal segregation processes. Lead and osmium isotopes will be used to tracers to ascertain whether sulfide mineralization resulted from increased silica activity associated with crustal contamination or whether sulfide mineralization was caused only by changes of temperature and oxygen fugacity. This research will help to elucidate processes of magma differentiation and mineralization associated with large ultramafic intrusions in general. Such intrusions are important sources of platinum group elements.