Million‐Year Scale Hydrothermal and Hydrocarbon Evolution Hosted Within Stratified Thermohydraulic Systems in Sedimented Ultraslow‐Spreading Settings, Svyatogor and Vestnesa Ridges
Year: 2026
Type: article
Abstract: Hydrothermal systems at ultraslow‐spreading ridges are poorly understood, especially where thick sediments overlay detachment faults. The International Ocean Discovery Program Expedition 403 obtained the longest sediment record in Atlantic‐Arctic ultraslow‐spreading systems, reaching ∼628 m below the seafloor. Heat‐flow measurements, fluid geochemistry, and mineralogical analyses, combined with seismic interpretation, revealed thermohydraulic systems within two contourite drifts on ridge flanks. The Svyatogor Ridge site exhibits extreme heat flow and crustal‐fluid migration from two detachment faults, accompanied by newly documented thermogenic hydrocarbons, resulting in stratified thermohydraulic systems. The Vestnesa Ridge site exhibits moderate heat flow, and partial crustal‐fluid migration suggests developing thermohydraulic systems. The results reveal complex, long‐lived hydrothermal systems in the present day with significant, previously poorly understood reservoirs of geological carbon and suggest their million‐year‐scale evolution. This study advances understanding of fluid dynamics, fluid‐sediment interactions, and carbon cycling in sedimented ultraslow‐spreading ridge environments.
Source: Geophysical Research Letters
DOI: 10.1029/2026gl123130
Institutions: Kyoto University, Rutgers, The State University of New Jersey, Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, James Madison University, National Institute of Oceanography and Applied Geophysics, Texas A&M University, Montclair State University, University of Florida, Ministry of Natural Resources, First Institute of Oceanography, Geological Survey of Japan, University of Tasmania, Institute for Marine and Antarctic Studies, Oklahoma State University, Marine Works Japan Ltd. (Japan), Kōchi University
Language: English
Subfield: Geology
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,190
OpenAlex ID: W7222829251