Stable isotope systematics in complex carbonates: Decoding geochemical processes and environmental conditions on Earth and other planets

复杂碳酸盐中的稳定同位素系统学：解码地球和其他行星上的地球化学过程和环境条件

• 批准号: RGPIN-2020-05810
• 负责人: Kim, SangTae
• 金额: $ 2.62万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=754858
• 关键词: Stable; isotope; systematics; complex; carbonates

Carbonates, such as corals and cave deposits, have been one of the most abundant minerals on Earth's surface throughout its geological history. Carbonates of varying chemical compositions were also found in some Martian meteorites. Therefore, carbonates have been extensively studied by earth scientists as a natural archive from which Earth and other planet's environmental history can be reconstructed. My research program has focused on studying stable isotope systematics of carbonate minerals to accurately decode geochemical and environmental signals hidden in the carbonate minerals. The main objective of my Discovery research proposal is to gain a detailed understanding of stable isotope systematics of structurally complex carbonate minerals, such as dolomite (CaMg(CO3)2) with two distinct cation layers and ikaite (CaCO3·6H2O) containing water in its crystal structure. Although they are less abundant than the well-known carbonate, or calcite, under Earth's surface condition, these structurally complex carbonates are still of geological importance and have high potential as geochemical proxies for probing geochemical processes and climatic/environmental conditions from terrestrial and extraterrestrial environments, including Antarctica and Mars. My research team will synthesize two complex carbonates, dolomite and ikaite, under various laboratory conditions by refining my laboratory's well-established synthesis methods and specialized facilities. These carbonates will then be examined carefully for their mineralogical and stable isotope characteristics with respective to their formation mechanisms and conditions to better interpret geochemical or environmental information from the carbonates. Cost-effective or time-efficient analytical techniques, without sacrificing the existing analytical precision, will also be explored for accurate stable isotopic analyses of the two target carbonates not only for my proposed research, but also for the benefit of a broader scientific community. I will also examine natural samples, obtained through national/international collaborations (e.g., ikaite from Antarctica), to validate our experimental findings and interpret geochemical data from natural carbonates to accurately uncover Earth and other planet's climate/environmental history. The outcome of my proposed research will open a new opportunity to use terrestrial or extraterrestrial carbonates that have been neglected or unexplored by the scientific community due to lack of scientific understanding and analytical challenges to uncover Earth and other planet's climate/environmental history. This is important to predict Earth's future climate variability, providing our government and public to prepare for relevant guidelines and regulations. My proposed research will also provide highly qualified personnel (HQP) with cutting-edge research experience and help them to develop essential analytical and research skills required for their future careers.

碳酸盐，例如珊瑚和洞穴沉积物，一直是地球表面上最丰富的矿物质之一。在一些火星陨石中也发现了不同化学成分的碳酸盐。因此，地球科学家已广泛研究了碳酸盐，作为一种自然档案，可以从中重建地球和其他行星的环境历史。我的研究计划的重点是研究碳酸盐矿物质的稳定同位素系统，以准确地解码隐藏在碳酸盐矿物质中的地球化学和环境信号。我发现研究建议的主要目的是详细了解结构复杂的碳酸盐矿物质的稳定同位素系统，例如白云岩（CAMG（CO3）2），其中有两个不同的阳离子层和Ikaite（Caco3·6H2O），其中包含其晶体结构中的水。尽管它们不如众所周知的碳酸盐或方解石在地球的表面状况下，但这些结构上复杂的碳酸盐仍然具有地质重要性，并且具有较高的潜力，作为地球化学代理，用于探测地球化学过程以及来自地面和外星环境的气候/环境条件，包括南极和火星。我的研究团队将在各种实验室条件下，通过完善实验室建立的合成方法和专业设施，在各种实验室条件下合成两种复杂的碳酸盐和Ikaite。然后，将仔细检查这些碳酸盐的矿物质学和稳定的同位素特征，并具有相对于其形成机制和条件，以更好地解释碳酸盐的地球化学或环境信息。还将探索具有成本效益或时间效率的分析技术，而不牺牲现有的分析精度，也将探索以确保对我提出的研究的两种目标碳酸盐的准确稳定同位素分析，也是为了获得更广泛的科学界的利益。我还将研究通过国家/国际合作（例如，来自南极洲的Ikaite）获得的天然样本，以验证我们的实验发现并解释从天然碳酸盐的地球化学数据，以准确发现地球和其他星球的气候/环境历史。我拟议的研究的结果将为科学界忽略或意外的地面或外星碳酸盐提供新的机会，因为缺乏科学理解和分析挑战来揭示地球和其他星球的气候/环境历史。这对于预测地球未来的气候变异性很重要，为我们的政府和公众提供准备相关指南和法规很重要。我提出的研究还将提供高素质的人员（HQP），以提供最先进的研究经验，并帮助他们发展未来职业所需的基本分析和研究技能。