Publication Date:
2022-05-25
Description:
Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Earth and Planetary Science Letters 431 (2015): 1730185, doi:10.1016/j.epsl.2015.09.025.
Description:
We have reviewed available visual information from the seafloor, and recently acquired
microbathymetry for several traverses across the Lucky Strike segment, to evaluate the
distribution of hydrothermal activity. We have identified a new on-axis site with diffuse
flow, Ewan, and anactive vent structure ~1.2 km from the axis, Capelinhos. These sites
are minor relative to the Main field, and our total heatflux estimate for all active sites
(200-1200 MW) is only slightly higher than previously published estimates. We also
identify fossil sites W of the main Lucky Strike field. A circular feature ~200 m in
diameter located on the flanks of a rifted off-axis central volcano, is likely a large and
inactive hydrothermal edifice, named Grunnus. We find no indicator of focused
hydrothermal activity elsewhere along the segment, suggesting that the enhanced melt
supply and the associated melt lenses, required to form central volcanoes, also sustain
hydrothermal circulation to form and maintain large and long-lived hydrothermal fields.
Hydrothermal discharge to the seafloor occurs along fault traces, suggesting focusing of
hydrothermal circulation in the shallow crust along permeable fault zones.
Description:
This work has been partly financed by ANR (France) Mothseim
Project NT05-3 42213 toJE, and by EU-RTN-MOMARNET to MC. The French Ministry of
Research financed ship, ROV and AUV time (Graviluck’06, MOMAR’08, Bathyluck’09,
MOMARSAT cruises in 2010-2015)
Repository Name:
Woods Hole Open Access Server
Type:
Preprint
Format:
application/pdf
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