Microbial Fe(III) reduction as a potential iron source from Holocene sediments beneath Larsen Ice Shelf

Jaewoo Jung, Kyu Cheul Yoo, Brad E. Rosenheim, Tim M. Conway, Jae Il Lee, Ho Il Yoon, Chung Yeon Hwang, Kiho Yang, Christina Subt, Jinwook Kim

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9 Citations (Scopus)


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.

Original languageEnglish
Article number5786
JournalNature communications
Issue number1
Publication statusPublished - 2019 Dec 1

Bibliographical note

Funding Information:
The present research was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (NRF-2018R1A2B6002036) and Antarctic Project of KOPRI (PE19030) to J.W.K. We thank the science parties and crews of KOPRI icebreaker R/V Araon for their extraordinary efforts to collect samples and data processing (KOPRI ANA03C). Especially, we express our deep appreciation to the late Dr. E. Domack and Dr. Yoon as co-chief scientists of Weddell Sea expedition for their tremendous contributions to this project.

Publisher Copyright:
© 2019, The Author(s).

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • General
  • Physics and Astronomy(all)


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