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

ABSTRACT: 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 dissolv

SUBMITTER: Jung J 

PROVIDER: S-EPMC6923428 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature