Boron based geochemical reconstructions of ocean pH and atmospheric CO₂ in the geological record ...

• Main Author: Trudgill, Molly Diana
• Format: Article in Journal/Newspaper
• Language: English
• Published: The University of St Andrews 2023
• Subjects: Boron isotopes; Ocean pH; CO₂; Mass extinction events; Paleoclimate; Ocean acidification; QC884.T8; Paleoclimatology; Boron > Isotopes; Atmospheric carbon dioxide
• Online Access: https://dx.doi.org/10.17630/sta/327; https://research-repository.st-andrews.ac.uk/handle/10023/27101

The boron isotope proxy is a valuable tool for reconstructing ocean pH and atmospheric CO₂ in Earth’s history. Its use on foraminifera in deep sea sediment cores has helped shape our understanding of Cenozoic carbon cycling and climate change, yet most of the extreme examples of biotic and climatic change are in the geological record, where the proxy has seen limited use. The boron isotope proxy’s widespread usage is also hindered by the challenges involved in traditional methods for measuring it: gravity microcolumns require exacting laboratory conditions and are time intensive. Older samples may have more variable matrices which can also be a problem for a gravity column. In order to expand the boron isotope proxy into a wider variety of matrices, Chapter 3 presents a new batch method for the purification of boron from its sample matrix. Together with methodological improvements for measurement by MC-ICPMS discussed in Chapter 2, these developments allow for measurement of a wide variety of samples with ...