Characterization of the End-Stages of Fractional Crystallization

分级结晶末期的表征

• 批准号: 0229702
• 负责人: William Meurer
• 金额: $ 11.13万
• 依托单位: University of Houston
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0229702&HistoricalAwards=false
• 关键词: Characterization; End; Stages; Fractional; Crystallization

MeurerEAR-0229702The Stillwater complex is a large body of layered mafic igneous rock formed by fractional crystallization of a basaltic magma--the most common type of magma generated in the Earth. As minerals grow and separate from a crystallizing basaltic magma, its composition becomes increasingly enriched in elements not included in the minerals, termed incompatible elements. Incompatible elements are used in the study of igneous rocks to document tectonic settings, extents of melting of a source region, and extents of fractional crystallization. This study will document the behavior of incompatible elements during the final stages of the crystallization of the Stillwater complex by examining the distribution, abundance, and composition of the last rocks to have crystallized. The Stillwater complex is of both economic and academic interest, as it hosts the bulk of the platinum reserves of the US and is a natural laboratory for understanding basaltic liquid crystallization. An understanding of the end stages of fractional crystallization in this intrusion will provide a more reliable basis for interpreting incompatible elements concentrations in igneous systems in general. It will also help in understanding how platinum was concentrated to more than 1000 times normal in the mineralized parts of this intrusion.

斯蒂尔沃特杂岩是一个大型的层状镁铁质火成岩体，由玄武岩浆分离结晶形成，玄武岩浆是地球上最常见的岩浆类型。当矿物从结晶的玄武岩浆中生长和分离出来时，其成分变得越来越富含矿物中不包含的元素，称为不相容元素。不相容元素用于火成岩研究，以记录构造背景、源区熔融程度和分离结晶程度。本研究将通过检查最后结晶的岩石的分布、丰度和成分，记录静水复合体结晶最后阶段不相容元素的行为。静水复杂的经济和学术利益，因为它拥有美国的大部分铂储量，是了解玄武岩液体结晶的天然实验室。在这个侵入体的分离结晶的结束阶段的理解将提供一个更可靠的基础，解释一般的火成岩系统中的不相容元素的浓度。这也将有助于了解铂是如何在这个侵入体的矿化部分集中到正常的1000倍以上。