Experimental evidence for kinetic effects on B/Ca in synthetic calcite: Implications for potential B(OH)4− and B(OH)3 incorporation

Uchikawa, Joji; Penman, Donald E.; Zachos, James C; Zeebe, Richard E.

doi:10.1016/j.gca.2014.11.022

Cited by 79 publications

(79 citation statements)

References 95 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on boron concentration data, Uchikawa et al (2015) suggest that partitioning of boron into calcite is best described in terms using total boron in solution rather than borate ion, especially at high precipitation rates. However preliminary d 11 B data on these same precipitates lie close to borate ion (Farmer et al 2015), inconsistent with substantial incorporation of boric acid.…”

Section: Boron Incorporation In Foraminiferamentioning

confidence: 99%

Boron Isotopes in Foraminifera: Systematics, Biomineralisation, and CO2 Reconstruction

Rae

2017

Advances in Isotope Geochemistry

View full text Add to dashboard Cite

The boron isotope composition of foraminifera provides a powerful tracer for CO 2 change over geological time. This proxy is based on the equilibrium of boron and its isotopes in seawater, which is a function of pH. However while the chemical principles underlying this proxy are well understood, its reliability has previously been questioned, due to the difficulty of boron isotope (d 11 B) analysis on foraminferal samples and questions regarding calibrations between d 11 B and pH. This chapter reviews the current state of the d 11 B-pH proxy in foraminfera, including the pioneering studies that established this proxy's potential, and the recent work that has improved understanding of boron isotope systematics in foraminifera and applied this tracer to the geological record. The theoretical background of the d 11 B-pH proxy is introduced, including an accurate formulation of the boron isotope mass balance equations. Sample preparation and analysis procedures are then reviewed, with discussion of sample cleaning, the potential influence of diagenesis, and the strengths and weaknesses of boron purification by column chromatography versus microsublimation, and analysis by NTIMS versus MC-ICPMS. The systematics of boron isotopes in foraminifera are discussed in detail, including results from benthic and planktic taxa, and models of boron incorporation, fractionation, and biomineralisation. Benthic taxa from the deep ocean have d 11 B within error of borate ion at seawater pH. This is most easily explained by simple incorporation of borate ion at the pH of seawater. Planktic foraminifera have d 11 B close to borate ion, but with minor offsets. These may be driven by physiological influences on the Electronic supplementary material The online version of this chapter

show abstract

Section: Boron Incorporation In Foraminiferamentioning

confidence: 99%

Boron Isotopes in Foraminifera: Systematics, Biomineralisation, and CO2 Reconstruction

Rae

2017

Advances in Isotope Geochemistry

View full text Add to dashboard Cite

show abstract

“…We measured boric acid, inorganic calcite, foraminiferal ooze, and monospecific planktic foraminifera (Globigerinoides sacculifer) samples previously used in the Foster et al (2013) intercomparison study. To complement this set, we also measured inorganic calcites precipitated from NaCl-CaCl 2 -B(OH) 3 -Na 2 CO 3 parent solutions of controlled pH and [Ca 2 + ] using a seeded calcite overgrowth technique (Uchikawa et al, 2015), JCp-1 (modern Porites sp. coral) and JCt-1 (Holocene Tridacna gigas giant clam) biogenic aragonite reference materials (Inoue et al, 2004;Hathorne et al, 2013;Gutjahr et al, 2014), and two samples of the benthic foraminifer Cibicidoides wuellerstorfi from Ocean Drilling Program Sites 1088 and 1264.…”

Section: Materials Usedmentioning

confidence: 99%

“…2c; linear regression R 2 = 0.49). It should be noted that the Mg/Ca and δ 18 O relationships are strongly driven by the inorganic calcites, which were precipitated from Mg-free and 18 O-depleted parent solutions (i.e., Mg/Ca = 0 mmol/mol, Table 1; Uchikawa et al, 2015) and generally show the greatest offset between N-TIMS and MC-ICP-MS δ 11 B values.…”

Section: Offsets Between Mc-icp-ms and N-timsmentioning

confidence: 99%

“…While this is strong evidence that the δ 11 B-pH sensitivity is independent of measurement technique, the ideal test for whether there are different δ 11 B-pH sensitivities between N-TIMS and MC-ICP-MS would be to compare results of homogenized splits of sample material grown under controlled pH conditions. We performed this test using three inorganic calcites precipitated from parent solutions covering a pH range of 8.37 to 8.65 (NBS scale) by Uchikawa et al (2015). δ 11 B borate was calculated for each experiment using the δ 11 B of experimental waters (−12.19 ± 0.32‰ measured by MC-ICP-MS), the fractionation of Klochko et al (2006), and the equilibrium constant pK B ⁎ calculated from experimental solution chemistries using PHREEQC (Parkhurst and Appelo, 2013) and the MINTEQA2 version 4 equilibrium speciation model that explicitly accounts for borate ion pairing (Allison et al, 1991).…”

Section: Implications For the δ 11 B-ph Proxymentioning

confidence: 99%

See 1 more Smart Citation

Single laboratory comparison of MC-ICP-MS and N-TIMS boron isotope analyses in marine carbonates

2016

Self Cite

View full text Add to dashboard Cite

Measurements of boron isotopes (δ 11 B) in marine carbonates are an important tool for reconstructing past ocean acidity and atmospheric carbon dioxide levels, but are challenging to obtain due to low boron concentrations and the presence of only two stable boron isotopes. Previous studies have observed differences in absolute δ 11 B values of marine carbonates measured via negative thermal ionization mass spectrometry (N-TIMS) and multicollector inductively coupled mass spectrometry (MC-ICP-MS) that are relatively large compared to magnitudes of δ 11 B variability in paleoceanographic studies. Here we investigate the cause of these δ 11 B offsets and implications for paleo-pH reconstructions by performing N-TIMS and MC-ICP-MS measurements within the same laboratory on a suite of eighteen homogenized samples, including inorganic calcites grown under controlled pH conditions and Quaternary planktic foraminifera. Results show that δ 11 B values between both measurement techniques are highly correlated (R 2 N 0.99), but calcite δ 11 B values are~0.5 to 2.7‰ lower when measured by MC-ICP-MS compared to N-TIMS. The δ 11 B offset between techniques cannot be attributed to procedural blank contribution, but the magnitude of offset moderately correlates with indicators of sample chemical composition, including B/Ca, Mg/Ca and δ 18 O (R 2 = 0.39 to 0.50). N-TIMS δ 11 B does not change with calcium addition to a biogenic carbonate sample, suggesting that varying calcium abundance between samples and standards is not the reason for N-TIMS "matrix effects". Correlation between δ 18 O and the δ 11 B offset is particularly apparent for calcites (R 2 = 0.71); the origin of this relationship is not clear, but is not likely due to 17 O interference. Although identifying the origin of measurement offsets requires further study, we demonstrate that such offsets do not affect the validity of δ 11 B data: The sensitivity of δ 11 B in inorganic calcite to pH is the same when measured by either technique, and paleo-pH reconstructed from δ 11 B measurements in planktic foraminifera is equivalent within uncertainty when a technique-specific constant offset is applied. Our results strongly indicate that δ 11 B measurements from both measurement techniques (N-TIMS and MC-ICP-MS) can be employed for paleo-pH reconstructions with equal confidence.

show abstract

“…(12) or a similar fit to both datasets is the most appropriate K D formulation. Calcite precipitation studies provide some support for the hypothesis that crystal growth rate or Ω Ar influences B/Ca partitioning (Ruiz-Agudo et al, 2012;Uchikawa et al, 2015Uchikawa et al, , 2017, but it is not yet known if these results can be extended 3 ] helps to account for the different solution chemistries and associated growth rates of the two abiogenic precipitation studies Holcomb et al, 2016), but Ω Ar or crystal growth rate may 15 be the true controlling factor (Watson, 2004;van der Weijden and van der Weijden, 2014 ] cf , may improve the accuracy of deriving calcifying fluid carbonate chemistry from boron systematics.…”

Section: Application To Deriving Coral Calcifying Fluid Carbonate Chementioning

confidence: 90%

Reviews and syntheses: Revisiting the boron systematics of aragonite and their application to coral calcification

DeCarlo¹,

Holcomb²,

McCulloch³

2018

Preprint

View full text Add to dashboard Cite

has not yet been a comprehensive analysis that considers both experimental datasets and explores the implications for interpreting coral skeletons. Here, we evaluate four potential K D formulations: three previously presented in the literature and one newly developed. We assess how well each formulation reconstructs the known fluid carbonate chemistry from the abiogenic experiments, and we evaluate the implications for deriving the carbonate chemistry of coral calcifying fluid. Three of the K D formulations performed similarly when applied to abiogenic aragonites precipitated from 10 seawater and to coral skeletons. Critically, we find that some uncertainty remains in understanding the mechanism of boron elemental partitioning between aragonite and seawater, and addressing this question should be a target of additional abiogenic precipitation experiments. Despite this, boron systematics can already be applied to quantify the coral calcifying fluid carbonate system, although uncertainties associated with the proxy system should be carefully considered for each application. Finally, we present a user-friendly computer code that calculates coral calcifying fluid carbonate chemistry, including propagation of 15 uncertainties, given inputs of boron systematics measured in coral skeleton.

show abstract

Experimental evidence for kinetic effects on B/Ca in synthetic calcite: Implications for potential B(OH)4− and B(OH)3 incorporation

Cited by 79 publications

References 95 publications

Boron Isotopes in Foraminifera: Systematics, Biomineralisation, and CO2 Reconstruction

Boron Isotopes in Foraminifera: Systematics, Biomineralisation, and CO2 Reconstruction

Single laboratory comparison of MC-ICP-MS and N-TIMS boron isotope analyses in marine carbonates

Reviews and syntheses: Revisiting the boron systematics of aragonite and their application to coral calcification

Contact Info

Product

Resources

About