Sulfate and phosphate oxyanions alter B/Ca and δ11B in inorganic calcite at constant pH: Crystallographic controls outweigh normal kinetic effects
Sulfate and phosphate oxyanions alter B/Ca and δ11B in inorganic calcite at constant pH: Crystallographic controls outweigh normal kinetic effects
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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
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发表时间：
2023
影响因子：
5
通讯作者：
Zeebe, Richard E.
中科院分区：
文献类型：
--
作者：
Uchikawa, Joji;Penman, Donald E.;Harper, Dustin T.;Farmer, Jesse R.;Zachos, James C.;Planavsky, Noah J.;Zeebe, Richard E.
我们报告了无机实验的新结果，其中探讨了几种氧阴离子对方解石中硼（分别为 B/Ca 和 δ11B）浓度和同位素组成的影响。这里检查的氧阴离子（硫酸根、磷酸根、硝酸根和亚硝酸根）的大小、电荷和几何构型各不相同，但它们都是包括海水在内的天然水溶液中常见的溶解成分。其中，已知抑制方解石成核/沉淀的硫酸盐和磷酸盐对方解石沉淀过程中的 B 掺入和同位素分馏具有显着影响。在其他条件不变的实验溶液中添加最多 5 mmol 硫酸盐和最多 2 μmol 磷酸盐，会导致方解石沉淀速率 R 相应下降，B/Ca 增加，并且方解石 δ11B 向计算出的 B(OH)4− δ11B 方向下降。这里观察到的 B/Ca 和 δ11B 随我们认为，在硫酸盐和磷酸盐存在下，B/Ca 和 δ11B 的矛盾且明显逆转的动力学趋势可归因于方解石晶格结构的变形，这是由于它们取代了晶格 CO3，从而增强了 B(OH)4− 的保留和最终结合。如果上述提出的机制在海水中生物方解石自然沉淀期间（例如有孔虫测试）同样有效，那么我们的新发现可能对使用 B/Ca 和 δ11B 重建海洋碳酸盐化学具有重要意义。尽管这需要进一步测试，但如果属实，新生代海水硫酸盐逐渐但大幅增加可能会导致有孔虫 B/Ca 和 δ11B 出现偏差。我们的实验数据还表明，Na+ 具有为 B(OH)4− 取代 CO3 提供电荷补偿的能力。然而，我们的数据还表明，Na + 浓度的变化并不能控制 B 的掺入程度。
We report new results from inorganic experiments in which the effects of several oxyanions on the concentration and isotopic composition of boron (B/Ca and δ11B, respectively) in calcite were explored. The oxyanions examined here (sulfate, phosphate, nitrate, and nitrite) differ in their size, charge, and geometric configuration, but they are all common dissolved constituents in natural aqueous solutions including seawater. Of those, sulfate and phosphate which are known to inhibit calcite nucleation/precipitation had pronounced impacts on the B incorporation and isotope fractionation during calcite precipitation. Additions of up to 5 mmol sulfate and up to 2 μmol phosphate into experimental solutions of otherwise unaltered condition caused comparable declines in calcite precipitation ratesR, increases in B/Ca, and decreases in calcite δ11B towards the calculated δ11B of B(OH)4−. The pattern of changes in B/Ca and δ11B as a function ofRobserved here is at odds with normal kinetic effects confirmed in previous studies, where B/Ca and δ11B were shown to increase and decrease, respectively, with an increase in degrees of calcite saturation in solutions and thusR. We argue that the paradoxical and apparently reversed kinetic trends in B/Ca and δ11B in the presence of sulfate and phosphate can be attributed to deformations of the calcite lattice structure due to their substitutions for lattice CO3, which in turn enhances the retainment and eventual incorporation of B(OH)4−. Our new findings could have important implications for paleo-reconstructions of ocean carbonate chemistry using B/Ca and δ11B, if the mechanism proposed above is similarly in effect during natural precipitation of biogenic calcite (e.g., foraminiferal tests) in seawater. Though this needs further testing, if true, the gradual but sizable increase in seawater sulfate over the Cenozoic could have biased foraminiferal B/Ca and δ11B. Our experimental data additionally indicate that Na+has the capability of providing charge compensations for substitutions of CO3by B(OH)4−. However, our data also demonstrate that changes in Na+concentration do not control the degrees of B incorporation.
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影响因子：
4.5
作者：
Salter M
通讯作者：
Salter M
硼与海洋碳酸钙的结合
DOI：
10.1007/978-3-319-64666-4_4
发表时间：
2018
期刊：
The Journal of Membrane Biology
影响因子：
--
作者：
O. Branson
通讯作者：
O. Branson
硫酸钠存在下方解石生长的原子力显微镜研究
DOI：
--
发表时间：
2008
期刊：
影响因子：
--
作者：
A. Vavouraki;C. Putnis;A. Putnis;P. Koutsoukos
通讯作者：
P. Koutsoukos
影响因子：
5
作者：
Evans, David;Gray, William R.;Allison, Nicola
通讯作者：
Allison, Nicola
影响因子：
3.5
作者：
Harper, D. T.;Honisch, B.;Zachos, J. C.
通讯作者：
Zachos, J. C.