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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Fossil black smoker yields oxygen isotopic composition of Neoproterozoic seawater

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Author(s):
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Hodel, F. [1, 2] ; Macouin, M. [2] ; Trindade, R. I. F. [1] ; Triantafyllou, A. [3] ; Ganne, J. [2] ; Chavagnac, V. [2] ; Berger, J. [2] ; Rospabe, M. [2] ; Destrigneville, C. [2] ; Carlut, J. [4] ; Ennih, N. [5] ; Agrinier, P. [4]
Total Authors: 12
Affiliation:
[1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Dept Geofis, BR-05508090 Sao Paulo - Brazil
[2] Univ Toulouse, GET, Observ Midi Pyrenees, CNRS, IRD, UPS, F-31400 Toulouse - France
[3] Univ Nantes, UMR CNRS 6112, Lab Planetol & Geodynam, F-44322 Nantes - France
[4] Univ Paris Diderot, Univ Sorbonne Paris Cite, Inst Phys Globe Paris, CNRS, UMR 7154, F-75005 Paris - France
[5] Univ Chouaib Doukkali, Fac Sci, Dept Geol, EGGPG, El Jadida 24000 - Morocco
Total Affiliations: 5
Document type: Journal article
Source: NATURE COMMUNICATIONS; v. 9, APR 13 2018.
Web of Science Citations: 3
Abstract

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. (AU)

FAPESP's process: 16/06114-6 - The Neoproterozoic Earth System and the rise of biological complexity
Grantee:Ricardo Ivan Ferreira da Trindade
Support type: Research Projects - Thematic Grants