Journal article
Enhanced primary productivity and perturbation of marine nitrogen cycling during the onset of the Cambrian SPICE event
Global and planetary change, Vol.233, 104365
02/2024
DOI: 10.1016/j.gloplacha.2024.104365
Abstract
New high-resolution paired carbonate carbon (δ13Ccarb) and nitrogen (δ15Nbulk) isotope records of the Steptoean Positive Carbon Isotope Excursion (SPICE) from the Laurentian epicontinental platform reveal a transient negative excursion in δ15Nbulk that closely aligns with the onset of the SPICE event and the initiation of the positive δ13Ccarb excursion. The negative excursion in δ15Nbulk identified here likely demonstrates an increase in microbially fixed nitrogen by diazotrophs, or cyanobacteria capable of N2 fixation, in the marine system due to a reduction in bioavailable recycled N through several processes at the onset of the biogeochemical event. Expansion of reducing environments during the initiation of the SPICE event would have liberated phosphorous previously bound to organic matter and/or marine iron oxy-hydroxides and simultaneously promoted an expansion of denitrification in oxygen-poor settings that would have reduced bioavailable N in the marine system. The enhanced delivery of phosphorous to the photic zone would have stimulated primary productivity, which would have also put additional pressure on the marine bioavailable N budget. These feedback systems would have combined to lower the marine N:P ratio such that diazotrophs would become a significant contributor to the total bioavailable N in the marine realm. The data presented here are the first demonstration of this significant perturbation to local marine nutrient cycling during the onset of the SPICE event and provide new insight into what may ultimately be a consistent set of biogeochemical triggers for major Paleozoic biogeochemical events.
Details
- Title: Subtitle
- Enhanced primary productivity and perturbation of marine nitrogen cycling during the onset of the Cambrian SPICE event
- Creators
- Gwen L. Barnes - University of IowaBradley D. Cramer - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Global and planetary change, Vol.233, 104365
- DOI
- 10.1016/j.gloplacha.2024.104365
- ISSN
- 0921-8181
- eISSN
- 1872-6364
- Grant note
- DOI: 10.13039/100000001, name: National Science Foundation, award: CAREER-1455030, EPSCOR-2119551; DOI: 10.13039/100018955, name: Department of Earth and Environmental Sciences, Robert J. Morrissey College of Arts and Sciences, Boston College
- Language
- English
- Electronic publication date
- 01/15/2024
- Date published
- 02/2024
- Academic Unit
- International Programs; Earth and Environmental Sciences
- Record Identifier
- 9984548407502771
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