The role of calcium in regulating marine phosphorus burial and atmospheric oxygenation.
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The marine phosphorus cycle plays a critical role in controlling the extent of global primary productivity and thus atmospheric pO2 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 pO2.
author list (cited authors)
Zhao, M., Zhang, S., Tarhan, L. G., Reinhard, C. T., & Planavsky, N.
complete list of authors
Zhao, Mingyu||Zhang, Shuang||Tarhan, Lidya G||Reinhard, Christopher T||Planavsky, Noah