Minerals as recorders of Earth and planetary processes

矿物作为地球和行星过程的记录者

• 批准号: RGPIN-2016-06048
• 负责人: Flemming, Roberta
• 金额: $ 2.4万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=710103
• 关键词: Minerals; recorders; Earth; planetary; processes

Minerals record history, on Earth and other rocky bodies in the solar system. Minerals record their own formation conditions and subsequent events such as deformation, heating, and interaction with fluids, via their compositions, crystal structures, cation order-disorder and textural relationships. My long-term research goal is to investigate the evolution of Earth and other planetary bodies in our solar system, by examining minerals from selected locations on Earth as well as in meteorites and returned samples from the moon, and eventually from asteroids and Mars. My research will focus on two themes: 1 Minerals as recorders of deformation: I will continue to lead the way in quantification of strain in minerals. I intend to quantify co-existing olivine and pyroxene in various settings, from the oldest solar system objects to evolved terrestrial samples. Studies will include chondritic meteorites as recorders of shock deformation on asteroids, martian meteorites as examples of deformation in a larger parent body, and mantle xenoliths as examples of deformation and dynamic recrystallization on Earth. Tandem grain size/strain measurements for olivine will elucidate mantle conditions. For olivine, pyroxene and terrestrial quartz, I aim to use 3D µXRD to compare deformation by meteorite impact (shock) against terrestrial tectonic deformation (strain), in order to discriminate between these effects. I will calibrate strain using minerals shocked to known shock pressures. These innovations will make µXRD a powerful probe of strain mechanism in Earth and planetary materials. 2 Minerals as recorders of temperature: I will interpret and quantify minerals as thermometers for the early solar system and terrestrial mantle rocks, by making systematic observations of cation distribution (order-disorder) for key mineral suites using NMR spectroscopy and diffraction methods, as well as energy models. Studying the co-existing minerals melilite and fassaite will reveal the cooling histories of Ca,Al-rich inclusions (CAIs) in meteorites, and of an unusual group of terrestrial alkaline ultramafic mantle rocks which are chemically similar to CAIs. In both cases these minerals record a complex history of crystallization and subsequent heating and metasomatism (fluid interaction). Parallel studies of these physically disparate, yet chemically similar, environments may elucidate the poorly-understood process of metasomatism. Independent estimates of temperature from spinel, fassaite and melilite in the same CAI would provide parent body cooling rate estimates, useful for modeling early solar system evolution. This research will place students at the forefront of current debates on the formation conditions and thermal evolution of early planetary bodies, the extent and variation of shock metamorphism in planetary materials, and the genesis of kimberlitic and other mantle-derived magmas.

矿物质记录历史，太阳系中的地球和其他岩石身体。矿物质记录了自己的形成条件以及随后的事件，例如通过其组成，晶体结构，阳离子订单序和质地关系，例如变形，加热和与流体的相互作用。我的长期研究目标是通过检查地球和陨石中选定位置的矿物质，并在月球中返回样品，有时甚至是从小行星和火星中返回样品，研究地球和其他行星体的演变。我的研究将重点介绍两个主题： 1个矿物作为变形记录： 我将继续领导矿物质菌株量化的道路。我打算在各种环境中量化共存的橄榄石和辉石，从最古老的太阳系对象到进化的陆地样品。研究将包括软骨陨石作为小行星上的休克变形的记录，火星陨石作为较大母体变形的例子，而地幔异甲岩是地球上变形和动态再结晶的例子。橄榄石的串联晶粒尺寸/应变测量结果将阐明地幔条件。对于橄榄石，辉石和陆生石英，我的目标是使用3D µXRD比较陨石撞击（休克）与陆生构造变形（应变）的变形，以区分这些作用。我将使用被震惊的矿物质校准应变为已知的冲击压力。这些创新将使µXRD成为地球和行星材料中应变机制的强大探针。 2个矿物作为温度记录： 我将使用NMR光谱和衍射方法以及能量模型对阳离子分布的系统观察（订购式）进行系统的观察来解释和量化矿物作为早期太阳系和地幔岩石的温度计。研究共存的矿物质和非洲岩矿物会揭示陨石中的CA，富含Al含量的夹杂物（CAI）的冷却史，以及在这两种情况下，在这两种情况下，在这两种情况下，都记录了一个复杂的结晶史和随后的供应和元主义互动（流体互动）。对这些物理上不同但化学相似的环境的平行研究可能会阐明变形的不良过程。在同一CAI中对尖晶石，Fassaite和Melilite的温度的独立估计将提供母体冷却率的估计，这对于对早期太阳系演变进行建模很有用。 这项研究将使学生在当前有关早期行星体的形成条件和热演化的辩论，行星材料中的冲击变质的程度和变化以及金伯里氏菌和其他地幔衍生的岩浆的起源。