Collaborative Research: RUI: Diffusion studies in baddeleyite and zircon

合作研究：RUI：斜锆石和锆石的扩散研究

• 批准号: 2313678
• 负责人: Daniele Cherniak
• 金额: $ 16.57万
• 依托单位: SUNY at Albany
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2313678&HistoricalAwards=false
• 关键词: Collaborative; Research; RUI; Diffusion; studies

The minerals zircon (ZrSiO4) and baddeleyite (ZrO2), although present only in low concentrations in most rocks, are important phases in geochronometry (measuring ages of rocks, meteorites, and geologic events). They incorporate trace and minor elements useful as geochemical indicators. Zircons in particular are very robust mineral grains and, since they can survive many types of geological events, are some of the oldest known materials on Earth. They have preserved information about geological processes that were occurring up to 4.4 billion years ago. Understanding the diffusion (mobility of atoms) behavior of key elements inside these minerals provides major constraints on how we interpret the measured ages, and chemical signatures of rocks and ancient geological events. There has been extensive study of diffusion of several chemical elements in zircon, even if some elements have been understudied. In contrast, there is a lack of diffusion data entirely for baddeleyite, which can yield complementary information to that gained from zircon analysis. Understanding diffusion in these minerals is essential for interpreting a wide range of geochronometric data, and evaluating and interpreting the chemical and isotopic signatures retained in these minerals over geologic timeframes. The main broader impacts of this work will be a contribution of important data that can be used by a wide range of scientists in diverse, but related, fields. The project will also provide an educational experience for undergraduate students in physics, engineering, and geosciences, as well as high school students from underserved communities. The proposed experiments build on a body of work measuring diffusion of a variety of elements in accessory minerals (minerals in generally minor abundance in rocks, but which incorporate elements important as geochronometers or geochemical tracers), to obtain a more complete geochemical picture of these critical minerals. The work also continues the refinement and application of accelerator-based ion beam techniques (Rutherford Backscattering Spectroscopy and Nuclear Reaction Analysis) in diffusion studies, exploiting the superior depth resolution of these analytical methods to access the slow diffusivities characteristic of many species in these materials. With the increasing application of microanalytical techniques to analyze natural samples and access fine-scale chemical and isotopic variations, diffusion data are a critical parameter in interpreting timing of geologic events, and evaluation of past chemical environments and thermal histories. These measurements will yield critical information for interpreting isotopic ages and thermal histories for baddeleyite, a mineral of interest but for which little diffusion data currently exist. The measurements of pentavalent cation diffusion in zircon will provide information about the resistance to chemical alteration of elements potentially useful as geochemical tracers, provide insight into substitutional mechanisms and charge balance for diffusion of altervalent cations. The Xe diffusion results may have implications for better interpreting Xe isotope systematics and noble gas behaviors in terrestrial and lunar samples, and understanding histories of the early Earth and Solar System. Zirconia also has utility as a refractory and optical material, so better understanding of its properties may have technological implications. The broader impacts of this work will be as a contribution of important data that can be used by a wide range of scientists in diverse, but related, fields in the geosciences, including thermochronology, geochronology, and studies of the early Earth and Solar System. The project will involve undergraduate students in research, providing experience in preparing samples, crystal synthesis, conducting experiments, using various analytical methods, and analyzing and interpreting data and presenting at research conferences. The project will also support a community outreach effort aimed at introducing local high school students to scientific research methods and Earth science.This project is jointly funded by Petrology & Geochemistry and Division of Earth Sciences to support projects that increase research capabilities, capacity and infrastructure at a wide variety of institution types, as outlined in the GEO EMBRACE DCL.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

矿物锆石（ZRSIO4）和Baddeleyite（ZRO2）虽然仅在大多数岩石中以低浓度的形式存在，但在地球体学（测量岩石，陨石和地质事件的年龄）中是重要的阶段。它们结合了有用的痕量和次要元素，可作为地球化学指标。特别是锆石是非常健壮的矿物晶粒，并且由于它们可以在许多类型的地质事件中生存，因此是地球上最古老的材料。他们保留了有关在44亿年前发生的地质过程的信息。了解这些矿物质内部关键要素的扩散（原子的流动性）行为对我们如何解释所测量的年龄以及岩石和古代地质事件的化学特征的主要限制。即使已经研究了一些元素，也已经进行了广泛研究锆石中几种化学元素的扩散。相比之下，完全缺乏扩散数据，完全用于Baddeleyite，这可以从锆石分析中产生补充信息。了解这些矿物质中的扩散对于解释广泛的地球学数据以及评估和解释在这些矿物质中保留在地质时间范围内的化学和同位素特征。这项工作的主要广泛影响将是重要数据的贡献，这些数据可以由多种多样但相关领域的科学家可以使用。该项目还将为物理，工程和地球科学的本科生以及来自服务不足社区的高中生提供教育经验。所提出的实验建立在测量各种元素矿物质（通常是岩石中通常较小的矿物质中的矿物）扩散的一系列工作，但它们包含了重要的元素，这些元素作为地球工程学或地球化学示踪剂很重要），以获得这些关键矿物质的更完整的地球化学图片。这项工作还延续了基于加速器的离子光束技术（路易福德反向散射光谱和核反应分析）的完善和应用，从而利用了这些分析方法的出色深度分辨率，以访问这些材料中许多物种的缓慢扩散特征。随着微分析技术在分析天然样品和访问精细化学和同位素变化的越来越多的应用中，扩散数据是解释地质事件时机以及评估过去化学环境和热历史的关键参数。这些测量结果将产生关键信息，以解释同位素年龄和BadDeleyite的热历史，这是一种感兴趣的矿物，但目前几乎没有扩散数据。锆石中五价阳离子扩散的测量将提供有关对地球化学示踪剂可能有用的化学改变的抗性的信息，提供了对替代机制的洞察力，并洞悉了替代机制和电荷平衡，以扩散替代阳离子。 XE扩散结果可能对更好地解释陆地和月球样本中的XE同位素系统和贵重气体行为有影响，并了解早期地球和太阳系的历史。氧化锆也具有难治性和光学材料的实用性，因此对其性质的更好理解可能具有技术意义。这项工作的更广泛的影响将是重要数据的贡献，这些数据可以由多种科学家在不同但相关的地球科学领域（包括热量人工学，地球人工学以及早期地球和太阳系的研究）中使用。该项目将涉及本科生研究，提供准备样本，晶体合成，进行实验，使用各种分析方法以及分析和解释数据并在研究会议上呈现的经验。该项目还将支持一项旨在向当地高中学生介绍科学研究方法和地球科学的社区外展工作。该项目由岩石学和地球化学和地球科学划分共同资助，以支持在各种各样的机构中，在各种各样的机构中，在地理上赢得了多种多样的奖励。使用基金会的智力优点和更广泛的影响评估标准进行评估。