权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

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

南极彭萨科拉山脉 Dufek 侵入体的 Nd、Os、Pb 和 Sr 同位素研究：层状镁铁质杂岩分异机制的重新评估

基本信息

批准号：
9219012
负责人：
Samuel Mukasa
金额：
$ 29.77万
依托单位：
Regents of the University of Michigan - Ann Arbor
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
1993
资助国家：
美国
起止时间：
1993-06-01 至 1997-05-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=9219012&HistoricalAwards=false
关键词：
Nd Os Pb Sr Isotopic

项目摘要

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.

该奖项支持对杜菲克层状超镁铁质侵入体的同位素研究。这项研究的目的是更好地了解大型镁铁质岩浆房中的火成作用，准确确定杜菲克侵入体的年龄，并评估侵入体中硫化物和铬铁矿矿化的成因。Dufek入侵是Karoo-Ferrar tholitic省的一部分，Karoo-Ferrar tholitic省是地球上已知的最大的此类省份之一。这项研究将涉及从岩石样品中分离出的矿物的超纯部分中进行高精度的钕、锶、铅和锶同位素的质谱分析。这些分析将被用来跟踪结晶和晶体分离过程中液体和积云(固体)相的成分变化。将使用铅和Os同位素作为示踪剂，以确定硫化物矿化是由地壳污染导致的二氧化硅活动增加所致，还是仅由温度和氧逸度的变化引起的。这项研究将有助于从总体上阐明与大型超镁铁质侵入岩有关的岩浆分异和成矿过程。这种侵入岩是铂族元素的重要来源。