Articles | Volume 18, issue 3
https://doi.org/10.5194/bg-18-775-2021
https://doi.org/10.5194/bg-18-775-2021
Technical note
 | 
02 Feb 2021
Technical note |  | 02 Feb 2021

Technical note: A universal method for measuring the thickness of microscopic calcite crystals, based on bidirectional circular polarization

Luc Beaufort, Yves Gally, Baptiste Suchéras-Marx, Patrick Ferrand, and Julien Duboisset

Related authors

Photic zone niche partitioning, stratification, and carbon cycling in the tropical Indian Ocean during the Piacenzian
Deborah N. Tangunan, Ian R. Hall, Luc Beaufort, Melissa A. Berke, Alexandra Nederbragt, and Paul R. Bown
EGUsphere, https://doi.org/10.5194/egusphere-2025-3557,https://doi.org/10.5194/egusphere-2025-3557, 2025
This preprint is open for discussion and under review for Climate of the Past (CP).
Short summary
Orbital-scale variability in the contribution of foraminifera and coccolithophores to pelagic carbonate production
Pauline Cornuault, Luc Beaufort, Heiko Pälike, Torsten Bickert, Karl-Heinz Baumann, and Michal Kucera
EGUsphere, https://doi.org/10.5194/egusphere-2025-198,https://doi.org/10.5194/egusphere-2025-198, 2025
Short summary
Eccentricity forcing on tropical ocean seasonality
Luc Beaufort and Anta-Clarisse Sarr
Clim. Past, 20, 1283–1301, https://doi.org/10.5194/cp-20-1283-2024,https://doi.org/10.5194/cp-20-1283-2024, 2024
Short summary
Technical note: A comparison of methods for estimating coccolith mass
Celina Rebeca Valença, Luc Beaufort, Gustaaf Marinus Hallegraeff, and Marius Nils Müller
Biogeosciences, 21, 1601–1611, https://doi.org/10.5194/bg-21-1601-2024,https://doi.org/10.5194/bg-21-1601-2024, 2024
Short summary
Toward a global calibration for quantifying past oxygenation in oxygen minimum zones using benthic Foraminifera
Martin Tetard, Laetitia Licari, Ekaterina Ovsepyan, Kazuyo Tachikawa, and Luc Beaufort
Biogeosciences, 18, 2827–2841, https://doi.org/10.5194/bg-18-2827-2021,https://doi.org/10.5194/bg-18-2827-2021, 2021
Short summary

Cited articles

Beaufort, L.: Weight estimates of coccoliths using the optical properties (birefringence) of calcite, Micropaleontology, 51, 289–298, 2005. 
Beaufort, L. and Heussner, S.: Coccolithophorids on the continental slope of the Bay of Biscay, I. Production, transport and contribution to mass fluxes, Deep Sea Res. Pt. II, 46, 2147–2174, 1999. 
Beaufort, L., Probert, I., and Buchet, N.: Effects of acidification and primary production on coccolith weight: implications for carbonate transfer from the surface to the deep ocean, Geochem. Geophys. Geosys., 8, 8, https://doi.org/10.1029/2006GC001493 2007. 
Beaufort, L., Probert, I., de Garidel-Thoron, T., Bendif, E. M., Ruiz-Pino, D., Metzl, N., Goyet, C., Buchet, N., Coupel, P., Grelaud, M., Rost, B., Rickaby, R. E. M., and de Vargas, C.: Sensitivity of coccolithophores to carbonate chemistry and ocean acidification, Nature, 476, 80–84, https://doi.org/10.1038/nature10295, 2011. 
Beaufort, L., Barbarin, N., and Gally, Y.: Optical measurements to determine the thickness of calcite crystals and the mass of thin carbonate particles such as coccoliths, Nat. Protoc., 9, 633–642, https://doi.org/10.1038/nprot.2014.028, 2014. 
Download
Short summary
The coccoliths are major contributors to the particulate inorganic carbon in the ocean. They are extremely difficult to weigh because they are too small to be manipulated. We propose a universal method to measure thickness and weight of fine calcite using polarizing microscopy that does not require fine-tuning of the light or a calibration process. This method named "bidirectional circular polarization" uses two images taken with two directions of a circular polarizer.
Share
Altmetrics
Final-revised paper
Preprint