Molecular simulations of kinetic stable calcium isotope fractionation at the calcite-aqueous interface

2020 ◽  
Vol 532 ◽  
pp. 119315 ◽  
Author(s):  
Laura Nielsen Lammers ◽  
Karol Kulasinski ◽  
Piotr Zarzycki ◽  
Donald J. DePaolo
Keyword(s):  
Isotope Fractionation ◽  
Molecular Simulations ◽  
Calcium Isotope ◽  
Stable Calcium

scholarly journals Stable calcium isotope fractionation during chemical weathering.

2021 ◽  
Author(s):  
Utpalendu Haldar ◽  
Ramananda Chakrabarti ◽  
Roberta L. Rudnick
Keyword(s):  
Chemical Weathering ◽  
Isotope Fractionation ◽  
Calcium Isotope ◽  
Stable Calcium

Ca isotope fractionation upon synthesis of carbonated apatite

2021 ◽  
Author(s):  
Michael E. Böttcher ◽  
Nikolaus Gussone ◽  
Anika C. Conrad ◽  
Iris Schmiedinger ◽  
Jens Fiebig ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Isotope Fractionation ◽  
Solid Phase ◽  
Experimental Studies ◽  
Apatite Formation ◽  
Calcium Isotope ◽  
Hydroxy Apatite ◽  
Carbonated Apatite ◽  
Batch Type ◽  
Synthetic Calcite

<p>Carbonated hydroxy-apatite (CHAP) was experimentally synthesized in batch-type set-ups by mixing of calcium (Ca)- and phosphate-bearing aqueous solutions and the transformation of calcite powder in aqueous solution between 11° and 65°C (Gussone et al., 2020). Compositional changes of the experimental solution and solid phase products were followed by elemental analysis, Raman spectroscopy, scanning-electron microscopy, and powder XRD. In the mixing experiments, crystallization of CHAP took place following the precipitation of metastable brushite as precursor that was then transformed into CHAP. In the transformation experiments using synthetic calcite as a precursor phase it was found that the reaction at pH values between 7.5 and 7.9 occurs via the direct replacement of calcium carbonate by CHAP.</p><p>Calcium isotope fractionation led to an enrichment of the light isotope in the solid CHAP compared to the aqueous solution by about -0.5 to -1.1 ‰, independent from the experimental approach, and the magnitude was essentially independent of temperature. The metastable brushite formed prior to transformation to CHAP showed a reduced fractionation compared to the CHAP. The observed Ca isotope fractionation into the CHAP lattice resembles that of natural phosphorites and lies within the range of the view existing theoretical and experimental studies.</p><p> </p><p>Reference: Gussone N., Böttcher M.E., Conrad A.C., Fiebig J., Pelz M., Grathoff G., Schmidt B.C. (2020) Calcium isotope fractionation upon experimental apatite formation. Chem. Geol., 551, 119737</p><p>The study was supported by German Science Foundation (DFG) to M.E.B and J.F. within the EXCALIBOR project (BO1548/8 and FI 948/7), and to N.G. (GU1035/10), and by Leibniz IOW.</p>

Rate-controlled calcium isotope fractionation in synthetic calcite

2004 ◽  
Vol 68 (22) ◽  
pp. 4665-4678 ◽  
Author(s):  
D. Lemarchand ◽  
G.J. Wasserburg ◽  
D.A. Papanastassiou
Keyword(s):  
Isotope Fractionation ◽  
Calcium Isotope ◽  
Rate Controlled ◽  
Synthetic Calcite

scholarly journals Naturally Occurring Stable Calcium Isotope Ratios in Body Compartments Provide a Novel Biomarker of Bone Mineral Balance in Children and Young Adults

2020 ◽  
Author(s):  
Rukshana Shroff ◽  
Mary Fewtrell ◽  
Alexander Heuser ◽  
Ana Kolevica ◽  
Alexander Lalayiannis ◽  
...  
Keyword(s):  
Young Adults ◽  
Bone Mineral ◽  
Isotope Ratios ◽  
Calcium Isotope ◽  
Mineral Balance ◽  
Naturally Occurring ◽  
Children And Young Adults ◽  
Body Compartments ◽  
Stable Calcium

scholarly journals Calcium isotope fractionation during coccolith formation inEmiliania huxleyi:Independence of growth and calcification rate

2007 ◽  
Vol 8 (5) ◽  
pp. n/a-n/a ◽  
Author(s):  
Gerald Langer ◽  
Nikolaus Gussone ◽  
Gernot Nehrke ◽  
Ulf Riebesell ◽  
Anton Eisenhauer ◽  
...  
Keyword(s):  
Isotope Fractionation ◽  
Calcium Isotope ◽  
Calcification Rate

scholarly journals Calcium isotope fractionation in coccoliths of cultured Calcidiscus leptoporus, Helicosphaera carteri, Syracosphaera pulchra and Umbilicosphaera foliosa

2007 ◽  
Vol 260 (3-4) ◽  
pp. 505-515 ◽  
Author(s):  
Nikolaus Gussone ◽  
Gerald Langer ◽  
Markus Geisen ◽  
Blair A. Steel ◽  
Ulf Riebesell
Keyword(s):  
Isotope Fractionation ◽  
Calcium Isotope
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