BIBLIOS

Document type
Journal articles

Document subtype
Full paper

Title
Sediment geochemistry reveals abundant off-axis hydrothermal fields on the ultraslow-spreading Southwest Indian Ridge

Participants in the publication
Shili Liao (Author)
Chunhui Tao (Author)
Ágata Alveirinho Dias (Author)
Dep. Geologia
IDL
Jia Liu (Author)
Xin Su (Author)
Shihui Lv (Author)
John W. Jamieson (Author)
Jianping Zhou (Author)
Xianming Deng (Author)
Jin Liang (Author)
Weifang Yang (Author)
Wei Li (Author)
Xianhui Yang (Author)

Summary
Off-axis inactive hydrothermal fields may harbor significant sulfide deposits. However, their distribution and abundance remain poorly constrained due to the challenges in their detection, as they lack associated hydrothermal plumes. Here, we present the first assessment on the abundance of off-axis inactive fields along four segments of the ultraslow-spreading Southwest Indian Ridge, based on a systematic sediment geochemistry survey. We found distinct dispersion patterns of hydrothermal Cu and Zn between magmatic- and detachment fault- controlled hydrothermal fields. These patterns are likely attributed to multiple factors, including variable physicochemical conditions of the hydrothermal plume,seafloor topography and bottom current. Up to 15 potential fields and their approximate locations were identified by the dispersion distance of hydrothermal Zn, Cu, and Fe. Among these fields, 8–14 are located off-axis, and 3–7 are likely newly identified inactive fields. The latter may have been active within the last 10 ka, with more than 60% spatially associated with detachment faults. The number of inactive fields is at least 2 times greater than previously reported for active fields within 40 km of the axial zone of the studied segments. As the studied sediments represent only the last 10 ka, significantly more buried inactive hydrothermal fields would be expected to be identified over longer time intervals. These findings significantly revise previous estimates of sulfide resources on ultraslow-spreading ridges.


Institution
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA

Where published
Earth and Planetary Science Letters

Publication Identifiers
ISSN - 0012-821X

Publisher
Elsevier BV



Document Identifiers
DOI - https://doi.org/10.1016/j.epsl.2024.118916
URL - http://dx.doi.org/10.1016/j.epsl.2024.118916

Tags
hydrothermal systems MOR