The origin of sulfur in Canary Island magmas and its implications for Earth's deep sulfur cycle

• 成果类型: Article
• 署名作者: Taracsak, Zoltan; Hartley, Margaret E.; Burgess, Ray; Edmonds, Marie; Longpre, Marc-Antoine; Monteleone, Brian D.; Tartese, Romain; Turchyn, Alexandra, V
• 署名单位: University of Cambridge; University of Manchester; City University of New York (CUNY) System; Queens College NY (CUNY); City University of New York (CUNY) System; Woods Hole Oceanographic Institution
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10366
• DOI: 10.1073/pnas.2416070122
• 发表日期: 2025-03-25
• 关键词: el hierro; isotope fractionation; mantle; eruption; sulfide; glasses; basalts; budget; lavas; melts

摘要

The global sulfur cycle plays a critical role in the redox evolution of Earth's surface and upper mantle, yet the distribution and origin of sulfur in the mantle remains largely unconstrained. El Hierro is a volcanic island in the Canary archipelago that is fed by sulfur-rich magmas. To constrain the origin of sulfur in these melts, we combine in situ sulfur isotope analyses with regression modeling. We calculate that undegassed El melts is 0.3%o to 1%o higher than magmas erupting at mid-ocean ridges. Mass balance and that on average 60% of sulfur in the source is of recycled origin. This recycled material should contain >1,800 mu g/g sulfur to satisfy isotopic constraints on its mass fraction in the mantle source. The sulfur and oxygen isotopic signature in serpentinites and sediments deviate significantly from the upper mantle, making them unsuitable candidates for the recycled material. An oxidized partial melt of recycled oceanic crust that retained one third of its sulfur budget after subduction zone processing can explain in the recycled component is necessary to produce metasomatic melts that are oxidizing enough to carry sufficient sulfur into the mantle source of ocean island basalts.