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

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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.