Mineralogy, petrology and isotope systematics of Proterozoic continental rift-related alkaline magmatism, Northwestern Ontario, Canada

加拿大安大略省西北部元古代大陆裂谷相关碱性岩浆作用的矿物学、岩石学和同位素系统学

• 批准号: RGPIN-2015-04732
• 负责人: Zurevinski, Shannon
• 金额: $ 1.46万
• 依托单位: Lakehead University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=613128
• 关键词: Mineralogy; petrology; isotope; systematics; Proterozoic

Niobium and rare earth element (REE) deposits are formed from highly differentiated magmatic fluids, such as pegmatites, carbonatites, and some peralkaline igneous rocks. Exploration of carbonatite and alkaline complexes across North America is increasing due to the demand of REEs for technological applications in Nd-magnets and diverse electronic components, and Nb for steel alloys. Each Nb- and REE deposit is unique, commonly presenting a variety of Nb- and REE minerals. Current exploration methods are often based on bulk rock analysis. This method is inadequate due to the compositional variation of Nb- and REE-bearing minerals in carbonatites and related alkaline rocks. It is important to understand the mineralogy of each of the deposits. This program is an integrated mineralogical and geochemical study of carbonatites and related alkaline rocks from Northwestern Ontario that are part of active advanced exploration programs for Nb- and REEs. It will involve in-situ mineralogical characterization (and chemical analysis of minerals), petrological investigations and isotopic (Nd-Sr-Hf-Pb) studies of tracer minerals occurring in the deposits. Two Northwestern Ontario Nb- and REE carbonatite intrusions, the Prairie Lake carbonatite complex, and the Chipman Lake carbonatite dikes and fenites), and two Nb-, REE-hosted multiphase alkaline intrusions (the Coldwell and Killala alkaline complexes) will be involved in this study. All intrusions share an important relationship to the Proterozoic Keweenawan Midcontinental rifting event. Understanding the unique mineralogy and isotopic variation in this geologically complex area will provide important insights into the source of the magma systems and the emplacement of the complexes during the large-scale continental rifting event. This is both beneficial to the exploration industry, and research into the Proterozoic Keweenawan Midcontinental rifting events, where little is understood with regards to the genetic relationship of the carbonatitic and alkaline complexes to the rifting event.

铌和稀土元素矿床形成于高分异岩浆流体中，如伟晶岩、碳酸岩和一些过碱性火成岩。由于稀土元素在钕磁铁和各种电子元件中的技术应用以及铌元素在钢合金中的需求，北美地区对碳酸盐岩和碱性配合物的勘探正在增加。每个铌和稀土矿床都是独一无二的，通常呈现各种铌和稀土矿物。目前的勘探方法往往是基于块状岩石分析。由于碳酸盐岩及相关碱性岩中含铌、稀土矿物的组成变化，这种方法并不适用。了解每一个矿床的矿物学是很重要的。