Feedback Between Carbon and Nitrogen Cycles During the Ediacaran Shuram Excursion
The middle Ediacaran Period records one of the deepest negative carbonate carbon isotope (δ13Ccarb) excursions in Earth history (termed the Shuram excursion). This excursion is argued by many to represent a large perturbation of the global carbon cycle. If true, this event may also have induced sign...
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Frontiers Media S.A.
2021-05-01
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| Online Access: | https://www.frontiersin.org/articles/10.3389/feart.2021.678149/full |
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| author | Dongtao Xu Xinqiang Wang Xinqiang Wang Xiaoying Shi Xiaoying Shi Yongbo Peng Yongbo Peng Eva E. Stüeken |
| author_facet | Dongtao Xu Xinqiang Wang Xinqiang Wang Xiaoying Shi Xiaoying Shi Yongbo Peng Yongbo Peng Eva E. Stüeken |
| author_sort | Dongtao Xu |
| collection | DOAJ |
| description | The middle Ediacaran Period records one of the deepest negative carbonate carbon isotope (δ13Ccarb) excursions in Earth history (termed the Shuram excursion). This excursion is argued by many to represent a large perturbation of the global carbon cycle. If true, this event may also have induced significant changes in the nitrogen cycle, because carbon and nitrogen are intimately coupled in the global ocean. However, the response of the nitrogen cycle to the Shuram excursion remains ambiguous. Here, we reported high resolution bulk nitrogen isotope (δ15N) and organic carbon isotope (δ13Corg) data from the upper Doushantuo Formation in two well-preserved sections (Jiulongwan and Xiangerwan) in South China. The Shuram-equivalent excursion is well developed in both localities, and our results show a synchronous decrease in δ15N across the event. This observation is further supported by bootstrapping simulations taking into account all published δ15N data from the Doushantuo Formation. Isotopic mass balance calculations suggest that the decrease in δ15N during the Shuram excursion is best explained by the reduction of isotopic fractionation associated with water column denitrification (εwd) in response to feedbacks between carbon and nitrogen cycling, which were modulated by changes in primary productivity and recycled nutrient elements through remineralization of organic matter. The study presented here thus offers a new perspective for coupled variations in carbon and nitrogen cycles and sheds new light on this critical time in Earth history. |
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| language | English |
| last_indexed | 2024-12-18T00:37:42Z |
| publishDate | 2021-05-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-d2dd7c93625b46718c456d47a4a5a5dc2022-12-21T21:26:57ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632021-05-01910.3389/feart.2021.678149678149Feedback Between Carbon and Nitrogen Cycles During the Ediacaran Shuram ExcursionDongtao Xu0Xinqiang Wang1Xinqiang Wang2Xiaoying Shi3Xiaoying Shi4Yongbo Peng5Yongbo Peng6Eva E. Stüeken7School of Earth Science and Resources, China University of Geosciences (Beijing), Beijing, ChinaSchool of Earth Science and Resources, China University of Geosciences (Beijing), Beijing, ChinaState Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Beijing), Beijing, ChinaSchool of Earth Science and Resources, China University of Geosciences (Beijing), Beijing, ChinaState Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences (Beijing), Beijing, ChinaInternational Center for Isotope Effect Research, Nanjing University, Nanjing, ChinaSchool of Earth Sciences and Engineering, Nanjing University, Nanjing, ChinaSchool of Earth and Environmental Sciences, University of St Andrews, St Andrews, United KingdomThe middle Ediacaran Period records one of the deepest negative carbonate carbon isotope (δ13Ccarb) excursions in Earth history (termed the Shuram excursion). This excursion is argued by many to represent a large perturbation of the global carbon cycle. If true, this event may also have induced significant changes in the nitrogen cycle, because carbon and nitrogen are intimately coupled in the global ocean. However, the response of the nitrogen cycle to the Shuram excursion remains ambiguous. Here, we reported high resolution bulk nitrogen isotope (δ15N) and organic carbon isotope (δ13Corg) data from the upper Doushantuo Formation in two well-preserved sections (Jiulongwan and Xiangerwan) in South China. The Shuram-equivalent excursion is well developed in both localities, and our results show a synchronous decrease in δ15N across the event. This observation is further supported by bootstrapping simulations taking into account all published δ15N data from the Doushantuo Formation. Isotopic mass balance calculations suggest that the decrease in δ15N during the Shuram excursion is best explained by the reduction of isotopic fractionation associated with water column denitrification (εwd) in response to feedbacks between carbon and nitrogen cycling, which were modulated by changes in primary productivity and recycled nutrient elements through remineralization of organic matter. The study presented here thus offers a new perspective for coupled variations in carbon and nitrogen cycles and sheds new light on this critical time in Earth history.https://www.frontiersin.org/articles/10.3389/feart.2021.678149/fullEdiacaranSouth ChinaDoushantuo FormationShuram excursionnitrogen isotopes |
| spellingShingle | Dongtao Xu Xinqiang Wang Xinqiang Wang Xiaoying Shi Xiaoying Shi Yongbo Peng Yongbo Peng Eva E. Stüeken Feedback Between Carbon and Nitrogen Cycles During the Ediacaran Shuram Excursion Frontiers in Earth Science Ediacaran South China Doushantuo Formation Shuram excursion nitrogen isotopes |
| title | Feedback Between Carbon and Nitrogen Cycles During the Ediacaran Shuram Excursion |
| title_full | Feedback Between Carbon and Nitrogen Cycles During the Ediacaran Shuram Excursion |
| title_fullStr | Feedback Between Carbon and Nitrogen Cycles During the Ediacaran Shuram Excursion |
| title_full_unstemmed | Feedback Between Carbon and Nitrogen Cycles During the Ediacaran Shuram Excursion |
| title_short | Feedback Between Carbon and Nitrogen Cycles During the Ediacaran Shuram Excursion |
| title_sort | feedback between carbon and nitrogen cycles during the ediacaran shuram excursion |
| topic | Ediacaran South China Doushantuo Formation Shuram excursion nitrogen isotopes |
| url | https://www.frontiersin.org/articles/10.3389/feart.2021.678149/full |
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