Document type
Journal articles
Document subtype
Full paper
Title
Sulfur isotopic compositions of sulfides along the Southwest Indian Ridge: implications for mineralization in ultramafic rocks
Participants in the publication
Teng Ding (Author)
Chunhui Tao (Author)
Ágata Alveirinho Dias (Author)
Dep. Geologia
IDL
Jin Liang (Author)
Jie Chen (Author)
Bin Wu (Author)
Dongsheng Ma (Author)
Rongqing Zhang (Author)
Jia Wang (Author)
Shili Liao (Author)
Yuan Wang (Author)
Weifang Yang (Author)
Jia Liu (Author)
Wei Li (Author)
Guoyin Zhang (Author)
Hui Huang (Author)
Summary
The recently explored Tianzuo hydrothermal field in serpentinized ultramafic rocks of the amagmatic segment of the ultraslow-spreading Southwest Indian Ridge displays high-temperature sulfide mineralization (isocubanite, sphalerite, and minor pyrrhotite) and low-temperature (pyrite and covellite) phases. Pyrite can be subdivided into pyrite-I and -II, with the former generally having a pseudomorphic texture after pyrrhotite and the latter typically growing around isocubanite, sphalerite, and pyrite-I or occurring as individual grains in quartz veinlets. The sulfide minerals have the greatest range of δ34S values (− 23.8 to 14.1‰), found so far among modern sediment-starved ridges, with distinct δ34S values for low- and high-temperature mineral phases. The high δ34S values of isocubanite (9.6 to 12.2‰) and sphalerite (9.1 to 14.1‰) suggest that sulfate, which precipitated from seawater during an early low-temperature phase of hydrothermal circulation, was the main sulfur source for these sulfides. Pyrite-II has the lowest and most variable δ34S values (− 23.8 to − 3.6‰), suggesting microbial sulfate reduction. Pyrite-I has variable and generally positive δ34S values (− 0.1 to 12.0‰), with sulfur being inherited from pyrrhotite from the original thermochemical reduction of sulfate, mixed with volcanogenic sulfur. Intermittent magmatism represented by gabbroic intrusions, and high permeability caused by well-developed fractures associated with detachment faults, contributed to the formation of sulfides in the Tianzuo hydrothermal field. These factors possibly control sulfide mineralization in amagmatic segments of ultraslow-spreading ridges.
Date of Submisson/Request
2020-04-28
Date of Acceptance
2020-10-22
Date of Publication
2020-10-31
Institution
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
Where published
Mineralium Deposita
Publication Identifiers
ISSN - 0026-4598
Publisher
Springer Science and Business Media LLC
Document Identifiers
DOI -
https://doi.org/10.1007/s00126-020-01025-0
URL -
http://dx.doi.org/10.1007/s00126-020-01025-0
Rankings
Web Of Science Q1 (2020) - 5.109 - GEOCHEMISTRY & GEOPHYSICS - SCIE
Web Of Science Q1 (2020) - 5.109 - MINERALOGY - SCIE
SCIMAGO Q1 (2020) - 1.51 - Economic Geology
SCIMAGO Q1 (2020) - 1.51 - Geochemistry and Petrology
SCIMAGO Q1 (2020) - 1.51 - Geophysics
SCOPUS Q1 (2020) - 7.8 - Geophysics
SCOPUS Q1 (2020) - 7.8 - Economic Geology
SCOPUS Q1 (2020) - 7.8 - Geochemistry and Petrology