Magmatic assemblages and metasomatic overprints

岩浆组合和交代叠印

• 批准号: 7721-2007
• 负责人: Martin, RobertFrancois
• 金额: $ 2.68万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=450156
• 关键词: Magmatic; assemblages; metasomatic; overprints

In broad terms, I focus on the mineralogy and petrology of crustal rocks, in particular those rocks formed in an extensional tectonic environment. I document what the magma produced, and how an aqueous phase exsolved from the melt or from outside interacts with the just-formed hot rocks as they cool and contract. Evolved igneous rocks like granites, nepheline syenites and carbonatites commonly involve a mixed crust + mantle provenance, which can best be evaluated using isotope geochemistry. The hydrothermal mobility of high-field-strength elements like Ta, Zr and Ti remains a contested area, and requires much more documentation in field-based studies. More basic rocks also bear the hydrothermal imprints, and mobility in those cases may well involve the platinum-group elements, of great economic importance. Field studies will focus on the Bancroft area of Ontario, the classic anorogenic Younger Granites of Nigeria, the granitic pegmatites of the Borborema Province, Brazil, and of Catalunya, Spain, the catazonal rocks of southern Madagascar, and the alkaline rocks of the Monteregian Province of Quebec. The crust also bears the imprint of localized impact-generated melting; a project on the Clearwater Lake craters in northern Quebec will shed light on the remelting of the metamorphic Archean basement and the limestone cover in the area. Many of the research projects address topics at the "cutting edge", about processes that shaped of crust of the Earth. At the same time, they touch on economic aspects, in particular those studies that address the platinum-group elements and the high field-strength elements, and thus have the potential of an impact on the optimization of mineral exploration for those commodities in Canada and elsewhere.

从广义上讲，我专注于地壳岩石的矿物学和岩石学，特别是那些在伸展构造环境中形成的岩石。我记录了岩浆产生了什么，以及从熔体中或从外部溶出的水相如何与刚刚形成的热岩相互作用，因为它们冷却和收缩。花岗岩、霞石正长岩和碳酸岩等演化成的火成岩通常具有壳幔混合物源，同位素地球化学是评价这种混合物源的最佳方法。高场强元素如Ta、Zr和Ti的热液流动性仍然是一个有争议的领域，需要更多的实地研究文件。更多的基性岩也带有热液印记，在这些情况下，流动性很可能涉及具有重要经济意义的铂族元素。实地研究将集中在安大略的班克罗夫特地区、尼日利亚的典型非造山年轻花岗岩、巴西博尔博雷马省和西班牙卡塔卢尼亚的花岗伟晶岩、马达加斯加南部的深成带岩石以及魁北克的蒙特雷吉亚省的碱性岩石。地壳还带有局部撞击产生的熔融痕迹;魁北克北方清水湖陨石坑的一个项目将揭示该地区变质太古代基底和石灰岩覆盖层的再熔融。许多研究项目涉及“前沿”的主题，即地壳形成的过程。与此同时，这些研究涉及经济方面，特别是涉及铂族元素和高场强元素的研究，因此有可能对加拿大和其他地方优化这些商品的矿物勘探产生影响。