Effects of carbonate chemistry and calcium ions on the boron partitioning between aqueous solution and inorganic calcium carbonate

溶解的硼是天然海水的重要成分，它与钙的比率可以用来估计过去大气中二氧化碳的浓度--这是气候研究中非常受欢迎的工具。然而，目前无机碳酸盐和生物碳酸盐中硼的结合机制仍然很不清楚，这影响了硼作为估算过去气候的工具的有效性。夏威夷大学的研究人员将致力于通过(1)进行受控无机沉淀实验来分析碳酸钙样品中的B/Ca比，(2)开发作为溶液化学功能的无机结合硼到碳酸盐中的理论热力学框架，以及(3)使用现有的生物系统和无机框架数据作为基线来解释生物成因碳酸盐中硼结合的特征，从而阐明这些过程。这项研究的结果将促进对碳酸盐矿物中微量元素掺入的基本了解，这对专注于反应机制、代理开发、气候学和全球生物地球化学循环的研究具有重要意义。广泛影响：该项目将为夏威夷大学的研究生和本科生提供科学研究经验和教育，并通过夏威夷大学和火奴鲁鲁的毕晓普博物馆开展公共宣传。

Dissolved boron is an important constituent of natural seawater, and its ratio with calcium can be used to estimate concentrations of atmospheric carbon dioxide in the past - a highly desired tool in climate research. However, at present, the mechanism of boron incorporation into inorganic, as well as biogenic carbonates is still largely unknown, impairing the utility of boron as a tool to estimate past climate. Researchers from University of Hawaii will aim to shed light on these processes by (1) conducting controlled inorganic precipitation experiments to analyze B/Ca ratios in calcium carbonate samples, (2) developing a theoretical, thermodynamic framework for the inorganic incorporation of boron into carbonates as a function of the solution chemistry, and (3) using available data of biological systems and the inorganic framework as a baseline to explain features of boron incorporation into biogenic carbonates. Results from this study will advance fundamental understanding of trace element incorporation into carbonate minerals, which has important implications for research focusing on reaction mechanisms, proxy development, climatology, and global biogeochemical cycles.Broader Impacts: This project will provide scientific research experience and education to graduate and undergraduate students at the University of Hawaii, and conduct public outreach through the University of Hawaii and Bishop Museum in Honolulu.