Volcanically hosted venting with indications of ultramafic influence at Aurora hydrothermal field on Gakkel Ridge

• Published in: Nature Communications
• Main Authors: German, Christopher R., Reeves, Eoghan P., Türke, Andreas, Diehl, Alexander, Albers, Elmar, Bach, Wolfgang, Purser, Autun, Ramalho, Sofia P., Suman, Stefano, Mertens, Christian, Walter, Maren, Ramirez-Llodra, Eva, Schlindwein, Vera, Bünz, Stefan, Boetius, Antje
• Format: Text
• Language: English
• Published: Nature Publishing Group UK 2022
• Subjects: Article; Arctic; Arctic Ocean; Gakkel Ridge
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9622739/; http://www.ncbi.nlm.nih.gov/pubmed/36316329; https://doi.org/10.1038/s41467-022-34014-0

The Aurora hydrothermal system, Arctic Ocean, hosts active submarine venting within an extensive field of relict mineral deposits. Here we show the site is associated with a neovolcanic mound located within the Gakkel Ridge rift-valley floor, but deep-tow camera and sidescan surveys reveal the site to be ≥100 m across—unusually large for a volcanically hosted vent on a slow-spreading ridge and more comparable to tectonically hosted systems that require large time-integrated heat-fluxes to form. The hydrothermal plume emanating from Aurora exhibits much higher dissolved CH(4)/Mn values than typical basalt-hosted hydrothermal systems and, instead, closely resembles those of high-temperature ultramafic-influenced vents at slow-spreading ridges. We hypothesize that deep-penetrating fluid circulation may have sustained the prolonged venting evident at the Aurora hydrothermal field with a hydrothermal convection cell that can access ultramafic lithologies underlying anomalously thin ocean crust at this ultraslow spreading ridge setting. Our findings have implications for ultra-slow ridge cooling, global marine mineral distributions, and the diversity of geologic settings that can host abiotic organic synthesis - pertinent to the search for life beyond Earth.