Frontiers in Marine Science | |
Foraminifera associated with cold seeps in marine sediments | |
Marine Science | |
Yinghan Lu1  Hailong Lu1  Hailin Yang1  Baoqi Huang2  Yujia Liu3  | |
[1] Beijing International Center for Gas Hydrate, School of Earth and Space Sciences, Peking University, Beijing, China;Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education (MOE), School of Earth and Space Sciences, Peking University, Beijing, China;School of Marine Science, Nanjing University of Information Science and Technology, Nanjing, China; | |
关键词: cold seep; marine foraminifera; methane seepage; species composition; secondary mineralization; stable isotopes; | |
DOI : 10.3389/fmars.2023.1157879 | |
received in 2023-02-03, accepted in 2023-04-06, 发布年份 2023 | |
来源: Frontiers | |
【 摘 要 】
Cold seep foraminifera have attracted considerable attention as they provide valuable insights into the study of cold seeps. This study provides a comprehensive overview of the manifestations of foraminifera in cold seep environments and methane seepage activities. Certain taxa of benthic foraminifera, such as Uvigerina, Bolivina, Bulimina, Chilostomella, Globobulimina, Nonionella, Melonis, Epistominella, Cibicidoides, and Globocassidulina, are known to inhabit geochemical conditions induced by methane-rich environments and may feed on associated methanotrophic microbial communities. Secondary mineralization on foraminifera shells is a widespread manifestation in seep sediments, and alters the microstructure, elementary composition, and isotopic signatures of foraminifera. On one hand, the precipitation of secondary authigenic Mg-rich, Mn-rich, Sr-rich, and Ba-rich calcite coatings have been observed on microfossils. On the other hand, micron-sized crystal pyrite and gypsum aggregates can also grow on the foraminifera walls. The negative δ13C and positive δ18O anomalies in both planktonic and benthic foraminifera from seep-associated sediments can serve as proxies for tracing past seepage activities, either in their live form or being adulterated by methane-derived authigenic carbonate after deposition. Seeping activities are recognized with a significant impact on benthic foraminifera, and the presence of cold seep-related species and significant isotopic anomalies in shells can be used to reconstruct past methane seepage events. Intensive methane seepage tends to suppress benthic foraminifera populations, while moderate intensity seepage may lead to a thriving benthic foraminiferal community, with hypoxia-enduring taxa such as Uvigerina, Melonis, and Bulimina being predominant. In contrast, oxygen-loving epibenthic taxa such as Cibicidoides often occur in areas of low methane flux. Compared to planktonic foraminifera, the single species of benthic foraminifera can provide a more comprehensive record of seepage evolution. Live benthic specimens are preferred for in-situ seep studies, while the superimposition of secondary minerals on the original shells should not be ignored when observing dead individuals. The significance of the evolution of methane seepage, changes in environmental parameters of the living habitat, and species sensitivity in cold seeps are emphasized in explaining the variation in foraminiferal assemblages and fluctuations in stable isotopes.
【 授权许可】
Unknown
Copyright © 2023 Lu, Yang, Huang, Liu and Lu
【 预 览 】
Files | Size | Format | View |
---|---|---|---|
RO202310101312365ZK.pdf | 7111KB | download |