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ORIGINAL RESEARCH article

Front. Mar. Sci.

Sec. Marine Biogeochemistry

Volume 12 - 2025 | doi: 10.3389/fmars.2025.1661587

This article is part of the Research TopicBiogeochemical Cycles in Marine Sediments: Insights from Elemental Enrichment, Mineralogy, and Stable Isotope VariabilityView all 5 articles

Organic carbon sources, transport, and mineralization in Kermadec Trench sediments

Provisionally accepted
Zijun  WuZijun Wu1*Shuo  BaiShuo Bai1Hengchao  XuHengchao Xu2Liang  DongLiang Dong3
  • 1Tongji University State Key Laboratory of Marine Geology, Shanghai, China
  • 2Sanya Institute of Deep-sea Science and Engineering Chinese Academy of Sciences, Sanya, China
  • 3Shanghai Jiao Tong University, Shanghai, China

The final, formatted version of the article will be published soon.

Hadal trenches are critical hotspots for organic carbon (OC) deposition and diagenesis, yet the mechanisms controlling carbon sequestration, particularly the role of episodic tectonic and volcanic events, remain poorly constrained. This study integrates geochemical analyses of solid sediments and porewater from sediment cores collected at six stations along two transects in the Kermadec Trench to characterize OC sources, transport, and mineralization dynamics within this hadal trench system. Our results reveal a distinct south-to-north sediment transport pattern along the trench axis, leading to an accumulation of marine-derived OC in the south and terrestrial OC in the north. Importantly, earthquake-triggered turbidity currents in the central trench and volcanic eruptions in the north dominate episodic disturbances, exerting primary control over sediment deposition and diagenesis. These downslope currents transport significant OC fluxes from continental slopes to trench axes, enhancing burial rates 20-fold relative to steady-state sedimentation and promoting OC preservation in axial domains. Our findings demonstrate that spatial heterogeneity in hadal carbon cycling is primarily governed by episodic geological events, providing essential insights for accurate quantification of carbon fluxes and their integration into global biogeochemical models.

Keywords: Organic carbon mineralization, Kermadec Trench, Event-driven deposition, Carbon burial, Volcanogenic sediments

Received: 08 Jul 2025; Accepted: 02 Oct 2025.

Copyright: © 2025 Wu, Bai, Xu and Dong. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Zijun Wu, wuzj@tongji.edu.cn

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