Variation in calcification of Reticulofenestra coccoliths over the Oligocene-Early Miocene ...

• Main Authors: Guitián, José, Fuertes, Miguel Ángel, Flores, José-Abel, Hernández-Almeida, Iván, Stoll, Heather
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2022
• Subjects: Newfoundland
• Online Access: https://dx.doi.org/10.3929/ethz-b-000582967; http://hdl.handle.net/20.500.11850/582967

Coccolithophores are calcifying marine phytoplankton whose intracellularly produced calcite plates, coccoliths, have been the dominant source of calcium carbonate in open-ocean settings since the Cretaceous. An open question is whether their calcification has been affected by changing environmental conditions over geological timescales such as variations in the ocean carbon system. Previous methods using circular polarized light microscopy allowed for only the thickness of small coccoliths thinner than 1.5 μm to be quantified, but prior to the Pliocene, a significant fraction of the coccoliths exceeded this thickness and have not been quantifiable. Here, we implement a new approach for calibration of circular polarized light microscopy enabling us to quantify coccoliths which feature calcite up to 3 μm thick. We apply this technique to evaluate the evolution of calcification in the Reticulofenestra from the early Oligocene to Early Miocene in exceptionally well-preserved sediments from the Newfoundland ... : Biogeosciences, 19 (20) ...