Iron fertilisation and biogeochemical cycles in the sub-Arctic northwest Pacific during the late Pliocene intensification of northern hemisphere glaciation

Bailey, Ian; Liu, Qingsong; Swann, George E.A.; Jiang, Zhaoxia; Sun, Youbin; Zhao, Xiang; Roberts, Andrew P.

Abstract

Increases in the low-field mass-specific magnetic susceptibility (χ), dropstones and the terrigenous sediment component from Ocean Drilling Program (ODP) Site 882 (~ 45°N) have been interpreted to indicate a major onset of ice-rafting to the sub-Arctic northwest Pacific Ocean during marine isotope stage (MIS) G6 (from ~ 2.75 Ma). In contrast, studies of the terrigenous content of sediments cored downwind of ODP Site 882 indicate that dust and disseminated volcanic ash deposition in the sub-Arctic Pacific increased markedly during MIS G6. To investigate the relative contribution of dust, volcanic ash and ice rafting to the Pliocene χ increase, we present new high-resolution environmental magnetic and ice-rafted debris records from ODP Sites 882 and 885. Our results demonstrate that the χ increase at both sites across MIS G6 is predominantly controlled by a previously overlooked mixture of aeolian dust and volcanic ash. Our findings call into question the reliability of χ as a proxy for ice-rafting to the North Pacific. They also highlight a previously undocumented link between iron fertilisation and biogeochemical cycling in the North Pacific at a key stage during intensification of late Pliocene northern hemisphere glaciation.

Citation

Bailey, I., Liu, Q., Swann, G. E., Jiang, Z., Sun, Y., Zhao, X., & Roberts, A. P. (2011). Iron fertilisation and biogeochemical cycles in the sub-Arctic northwest Pacific during the late Pliocene intensification of northern hemisphere glaciation. Earth and Planetary Science Letters, 307(3-4), 253-265. https://doi.org/10.1016/j.epsl.2011.05.029

• Journal Article Type: Article
• Online Publication Date: Jun 2, 2011
• Publication Date: Jul 1, 2011
• Deposit Date: Feb 13, 2025
• Journal: Earth and Planetary Science Letters
• Print ISSN: 0012-821X
• Electronic ISSN: 0012-821X
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 307
• Issue: 3-4
• Pages: 253-265
• DOI: https://doi.org/10.1016/j.epsl.2011.05.029
• Public URL: https://nottingham-repository.worktribe.com/output/23525620
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0012821X11003128?via%3Dihub