Collaborative Research: Effects of sulfate on boron incorporation into calcite: Relevance and implications for foraminiferal boron isotope and B/Ca paleo-proxies.

合作研究：硫酸盐对硼掺入方解石的影响：有孔虫硼同位素和 B/Ca 古代理的相关性和影响。

• 批准号: 2024574
• 负责人: Noah Planavsky
• 金额: $ 6.94万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-15 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2024574&HistoricalAwards=false
• 关键词: Collaborative; Research; Effects; sulfate; boron

Microscopic fossil shells can provide records of ocean chemistry in the past. The boron to calcium ratio (B/Ca) and boron isotopic composition (d11B) of such fossils are widely used to record seawater pH and carbon chemistry. These records provide valuable insights into past changes in atmospheric carbon dioxide and the global carbon cycle. Recent experiments show that the addition of sulfate ions increases the amount of B incorporated into carbonate minerals. The proposed study will explore how and why B incorporation is enhanced by sulfate. It also will examine if sulfate influences the d11B of synthetic calcite. And the study will use culture experiments to assess whether the boron chemistry of biogenic calcite is impacted by seawater sulfate. This will be a crucial test of the reliability of d11B and B/Ca fossil records, since seawater sulfate has varied substantially over the last 60 million years. The project also will provide training for graduate and undergraduate students and educational outreach activities to local communities. This study integrates inorganic calcite precipitation experiments and foraminiferal culturing to investigate the mechanistic link between B incorporation and sulfate (SO42−) and its relevance to biological systems using benthic foraminifers as the model organism. First, we will comprehensively analyze δ11B, B/Ca and other trace elements (S/Ca and Na/Ca) of synthetic calcite precipitated in solutions added with aqueous B and variable amounts of SO42−. Second, we will grow sub-mm scale calcite crystals in growth solutions added with aqueous B and/or SO42−, and compare the intra-crystal distribution/zonation of B and S using a secondary ion mass spectrometer (SIMS). Finally, we will culture a well-studied species of benthic foraminifera under various seawater SO42− concentrations. If foraminiferal δ11B and B/Ca are indeed sensitive to changes in seawater SO42−, we will provide the equations to account for the SO42− effect.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.

微观化石壳过去可以提供海洋化学的记录。此类化石的硼与钙比（B/CA）和硼同位素组成（D11B）被广泛用于记录海水pH和碳化学。这些记录为大气二氧化碳和全球碳周期的过去变化提供了宝贵的见解。最近的实验表明，添加硫酸盐离子会增加掺入碳酸盐矿物质的B量。拟议的研究将探讨硫酸盐如何增强B感染的方式和原因。它还将检查硫酸盐是否影响合成钙的D11b。该研究将使用培养实验来评估生物钙的硼化学是否受到硫酸海水的影响。这将是对D11B和B/CA化石记录的可靠性的关键测试，因为硫酸海水在过去的6000万年中有很大不同。该项目还将为研究生和本科生提供培训，并向当地社区提供教育外展活动。这项研究将无机钙降水实验和有孔虫培养物结合起来，以研究B掺入和硫酸盐和硫酸盐（SO42-）之间的机械联系及其与生物系统的相关性，使用底栖有孔虫作为模型组织。首先，我们将全面分析合成钙方解石精度的Δ11b，b/ca和其他含有水性B和可变量的SO42-的溶液中的微量元素（S/Ca和Na/ca）。其次，我们将在添加B和/或SO42-水溶液中种植亚MM量表钙晶体，并使用二级离子质谱仪（SIMS）比较B和S的晶体内分布/分区。最后，我们将在各种海水SO42-浓度下培养底栖有孔虫的良好物种。如果有孔虫Δ11b和b/ca确实对海水SO42-的变化敏感，我们将提供方程式以说明SO42-效果。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的审查标准来通过评估来诚实地认为通过评估来诚实地支持。

项目成果

Sulfate and phosphate oxyanions alter B/Ca and δ11B in inorganic calcite at constant pH: Crystallographic controls outweigh normal kinetic effects

硫酸盐和磷酸盐氧阴离子在恒定 pH 条件下改变无机方解石中的 B/Ca 和 Ύ´11B：晶体学控制超过正常动力学效应

• DOI: 10.1016/j.gca.2022.12.018
• 发表时间: 2023
• 期刊: Geochimica et Cosmochimica Acta
• 影响因子: 5
• 作者: Uchikawa, Joji;Penman, Donald E.;Harper, Dustin T.;Farmer, Jesse R.;Zachos, James C.;Planavsky, Noah J.;Zeebe, Richard E.
• 通讯作者: Zeebe, Richard E.