Mafic magmatism in layered intrusions through time and space

时空层状侵入中的镁铁质岩浆作用

• 批准号: RGPIN-2018-04664
• 负责人: Scoates, James
• 金额: $ 3.13万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=688659
• 关键词: Mafic; magmatism; layered; intrusions; through

Terrestrial planetary crusts are dominated by rocks crystallized from basaltic magma. These magmas form by partial melting of the mantle and they erupt at the Earth's surface where they produce spectacular volcanic features, including the mountainous mid-ocean ridges, linear chains of hotspot volcanoes, and vast outpourings of flood basalts that may be triggers for catastrophic biosphere collapse. Most basaltic magmas do not erupt and instead they stall and crystallize in shallow to deep crustal reservoirs such as layered intrusions that preserve stunning rock records of the processes by which magma evolves. The overall goal of my proposed research program is to evaluate the timescales and processes by which basaltic magmas form planetary crusts. This will be accomplished through investigation of the geochronology and geochemistry of select layered intrusions. The research will take advantage of analytical developments, especially trace element and isotopic micro-analysis, and utilize state-of-the-art instrumentation at the Pacific Centre for Isotopic and Geochemical Research.******Key to understanding the relationships between layered intrusions and crustal evolution is (1) the duration and rate at which magmas accumulate in the crust, (2) the thermal history of individual intrusions, and (3) the composition of the mantle source, all of which remain poorly constrained for layered intrusions. I will develop integrated time-temperature-composition frameworks for individual intrusions that will serve as benchmarks for comparison across the geological record. I will study a range of ancient (Archean) to young (Cenozoic) intrusions, including those where the basic principles of crystallization in magma chambers have been established (Skaergaard, Stillwater) and Canadian intrusions that provide opportunities to test current and emerging paradigms on the physical state of magma reservoirs (Fox River, Polaris). I will also investigate the use of non-traditional stable isotopes as a new geochemical tool for tracking mineral-controlled processes in layered intrusions that will yield novel insights into their crystallization conditions and sequences.******Layered intrusions contain world-class deposits of chromium, platinum group elements, and vanadium, metals that are vital to society in general. The results of this research will have direct implications for the origin of magmatic ore deposits in intrusions in Canada and elsewhere in the world. The ultimate goal of this work is to provide new scientific constraints on the timescales and pathways of magmatic processes and cooling that produce the striking rocks present in layered intrusions. The results will be used to challenge basic concepts of magma evolution and development of the Earth's crust through time and space.

地壳陆层岩层以玄武岩岩浆结晶为主。这些岩浆通过地幔的部分熔融形成，它们在地球表面爆发，在那里产生壮观的火山特征，包括山上的山山山脊，热点火山的线性链，以及巨大的洪水盆地，可能会导致灾难性生物环崩溃。大多数玄武岩岩浆都不会爆发，相反，它们在浅层到深层的地壳储层中停滞不前，例如分层的侵入物，可保留岩浆演变的过程的惊人岩石记录。我提出的研究计划的总体目标是评估玄武岩岩浆形成行星地壳的时间标准和过程。这将通过研究某些分层入侵的年代学和地球化学来实现。这项研究将利用分析发展，尤其是同位素的微型分析，并利用太平洋同位素和地球化学研究中心的最先进的仪器。地幔源，所有这些层对分层侵入的限制仍然很差。我将为各个入侵的综合时间复合框架开发，这些框架将作为整个地质记录的基准。我将研究一系列古老的（天堂）到年轻的（库诺卡）入侵，包括建立岩浆腔室中结晶的基本原理（Skaergaard，Stillwater）和加拿大侵入的基本原理，这些侵入者提供了测试当前和新兴范式的岩浆储层状态（Fox Reservoirs（Fox River）（Fox River，Polaris，Polaris）的范式的机会。我还将调查使用非传统稳定同位素作为一种新的地球化学工具，用于跟踪分层的侵入中的矿物控制过程，这些工艺将对其结晶条件和序列产生新的见解。******层次的进取量包含镀铬的世界一流沉积物，包含镀铬，铂金组和瓦纳德元素和瓦纳德元素，var vitals，是一个社会，是vitals nevical ins vital vital vicital ins vital vital。这项研究的结果将直接影响加拿大和世界其他地方的岩浆矿床的起源。这项工作的最终目标是在岩浆过程的时间尺度和途径上提供新的科学限制，并在分层入侵中产生引人注目的岩石。结果将用于挑战岩浆进化的基本概念和在时间和空间中的地壳发展。