%0 Journal Article
%9 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES
%A Hodel, F.
%A Macouin, M.
%A Trindade, R. I. F.
%A Triantafyllou, A.
%A Ganne, Jérôme
%A Chavagnac, V.
%A Berger, J.
%A Rospabe, M.
%A Destrigneville, C.
%A Carlut, J.
%A Ennih, N.
%A Agrinier, P.
%T Fossil black smoker yields oxygen isotopic composition of Neoproterozoic seawater
%D 2018
%L fdi:010072752
%G ENG
%J Nature Communications
%@ 2041-1723
%K MAROC
%M ISI:000429921000010
%P art. 1453 [7 ]
%R 10.1038/s41467-018-03890-w
%U https://www.documentation.ird.fr/hor/fdi:010072752
%> https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers18-05/010072752.pdf
%V 9
%W Horizon (IRD)
%X The evolution of the seawater oxygen isotopic composition (delta O-18) through geological time remains controversial. Yet, the past delta O-18(seawater) is key to assess past seawater temperatures, providing insights into past climate change and life evolution. Here we provide a new and unprecedentedly precise delta O-18 value of -1.33 +/- 0.98% for the Neoproterozoic bottom seawater supporting a constant oxygen isotope composition through time. We demonstrate that the Ait Ahmane ultramafic unit of the ca. 760 Ma Bou Azzer ophiolite (Morocco) host a fossil black smoker-type hydrothermal system. In this system we analyzed an untapped archive for the ocean oxygen isotopic composition consisting in pure magnetite veins directly precipitated from a Neoproterozoic seawater-derived fluid. Our results suggest that, while delta O-18(seawater) and submarine hydrothermal processes were likely similar to present day, Neoproterozoic oceans were 15-30 degrees C warmer on the eve of the Sturtian glaciation and the major life diversification that followed.
%$ 064 ; 032