The role of calcium in regulating marine phosphorus burial and atmospheric oxygenation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32376824.
- Also identified by DOI 10.1038/s41467-020-15673-3 and PMC identifier 7203231.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The marine phosphorus cycle plays a critical role in controlling the extent of global primary productivity and thus atmospheric pO<sub>2</sub> on geologic time scales. However, previous attempts to model carbon-phosphorus-oxygen feedbacks have neglected key parameters that could shape the global P cycle. Here we present new diagenetic models to fully parameterize marine P burial. We have also coupled this diagenetic framework to a global carbon cycle model. We find that seawater calcium concentration, by strongly influencing carbonate fluorapatite (CFA) formation, is a key factor controlling global phosphorus cycling, and therefore plays a critical role in shaping the global oxygen cycle. A compilation of Cenozoic deep-sea sedimentary phosphorus speciation data provides empirical support for the idea that CFA formation is strongly influenced by marine Ca concentrations. Therefore, we propose a previously overlooked coupling between Phanerozoic tectonic cycles, the major-element composition of seawater, the marine phosphorus cycle, and atmospheric pO<sub>2</sub>.