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Weight estimates of coccoliths using the optical properties (birefringence) of calcite

2005; Micropaleontology Press; Volume: 51; Issue: 4 Linguagem: Inglês

10.2113/gsmicropal.51.4.289

1937-2795

Luc Beaufort,

Marine and coastal ecosystems

Research Article| October 01, 2005 Weight estimates of coccoliths using the optical properties (birefringence) of calcite Luc Beaufort Luc Beaufort CNRS-Université Aix-Marseille III, CEREGE, Europôle de l'Arbois, BP 80, 13545 Aix-en-Provence Cedex 04, France email: beaufort@cerege.fr Search for other works by this author on: GSW Google Scholar Micropaleontology (2005) 51 (4): 289–297. https://doi.org/10.2113/gsmicropal.51.4.289 Article history first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Luc Beaufort; Weight estimates of coccoliths using the optical properties (birefringence) of calcite. Micropaleontology 2005;; 51 (4): 289–297. doi: https://doi.org/10.2113/gsmicropal.51.4.289 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyMicropaleontology Search Advanced Search Abstract The coccolithophores are among the few organisms of the phytoplankton to calcify. Although together with the planktonic foraminifera they dominate calcite production in the open ocean, the amount of calcite they secrete is difficult to determine. The amount of calcite in the form of coccoliths that is dissolved during sedimentation is also difficult to estimate as is the amount of calcite represented by sedimented coccoliths. Because of their minuteness, coccoliths cannot be directly weighed. Instead, indirect methods must be used to estimate their weight.I describe here a method that allows quick estimations of the weight of individual coccoliths, based on the measure of their brightness when viewed in cross-polarized light. This birefringence method can only be applied to the group Heliolithae (excluding some of the coccoliths produced in the Family Coccolithaceae). For Coccolithaceae and some Ortholithae an estimate of the weight can be made using a correcting factor. The birefringence method is highly reproducible (+/− 0.13pg). However, a significant systematic error of 13.5% may occur when coccoliths with asymmetrical appearance in cross polarized light (e.g., Helicospheara carteri) are not measured in specific orientations. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.