Element cycles, Geochemistry, Marine chemistry
Digital Object Identifier (DOI)
Recent recession of the Larsen Ice Shelf C has revealed microbial alterations of illite in marine sediments, a process typically thought to occur during low-grade metamorphism. In situ breakdown of illite provides a previously-unobserved pathway for the release of dissolved Fe2+ to porewaters, thus enhancing clay-rich Antarctic sub-ice shelf sediments as an important source of Fe to Fe-limited surface Southern Ocean waters during ice shelf retreat after the Last Glacial Maximum. When sediments are underneath the ice shelf, Fe2+ from microbial reductive dissolution of illite/Fe-oxides may be exported to the water column. However, the initiation of an oxygenated, bioturbated sediment under receding ice shelves may oxidize Fe within surface porewaters, decreasing dissolved Fe2+ export to the ocean. Thus, we identify another ice-sheet feedback intimately tied to iron biogeochemistry during climate transitions. Further constraints on the geographical extent of this process will impact our understanding of iron-carbon feedbacks during major deglaciations.
This work is licensed under a Creative Commons Attribution 4.0 License.
Was this content written or created while at USF?
Citation / Publisher Attribution
Nature Communications, v. 10, art. 5786
Scholar Commons Citation
Jung, Jaewoo; Yoo, Kyu-Cheul; Rosenheim, Brad E.; Conway, Tim M.; Lee, Jae Il; Yoon, Ho Il; Hwang, Chung Yeon; Yang, Kiho; Subt, Christina; and Kim, Jinwook, "Microbial Fe(III) Reduction as a Potential Iron Source from Holocene Sediments Beneath Larsen Ice Shelf" (2019). Marine Science Faculty Publications. 2418.