FN Archimer Export Format
PT J
TI Fluid Flow, Mineralization and Deformation in an Oceanic Detachment Fault: Microtextural, Geochemical and Isotopic Evidence From Pyrite at 13°30′N on the Mid‐Atlantic Ridge
BT 
AF Martin, Andrew J.
   Jamieson, John W.
   Petersen, Sven
   Fayek, Mostafa
   Escartin, Javier
AS 1:1;2:2;3:3;4:4;5:5;
FF 1:;2:;3:;4:;5:;
C1 Geoscience University of Nevada Las Vegas NV, USA
   Department of Earth Sciences Memorial University of Newfoundland St. John's NL, Canada
   GEOMAR, Helmholtz Centre for Ocean Research Keil Kiel ,Germany
   Department of Earth Sciences University of Manitoba Winnipeg MB ,Canada
   Laboratoire de Géologie (CNRS UMR8538) Ecole Normale Supérieure de Paris PSL University Paris ,France
C2 UNIV NEVADA, USA
   UNIV NEWFOUNDLAND, CANADA
   IFM GEOMAR, GERMANY
   UNIV MANITOBA, CANADA
   UNIV PARIS, FRANCE
IN DOAJ
IF 3.5
TC 0
UR https://archimer.ifremer.fr/doc/00869/98128/107420.pdf
   https://archimer.ifremer.fr/doc/00869/98128/107421.docx
   https://archimer.ifremer.fr/doc/00869/98128/107422.xlsx
LA English
DT Article
CR ODEMAR
BO Pourquoi pas ?
DE ;detachment fault;geochemistry;pyrite;oceanic core complex;trace metals;sulfur isotopes
AB Hydrothermal fluids in ultramafic‐hosted hydrothermal systems associated with oceanic detachment faults can be more oxidizing compared to mafic‐hosted vent sites. These fluids form a mineral assemblage of pyrite, magnetite and hematite. At 13°30′N on the Mid‐Atlantic Ridge, chlorite‐quartz breccias recovered from an exposed fault scarp contain pyrite, with abundant magnetite and hematite, indicating that the redox of the fluids was variable. In primary micron‐scale zonations in pyrite, Ni, Co, and Se have a decoupled relationship, recording fluctuations in the chemical composition and temperature of hydrothermal fluid as the grains grew. Secondary zonations that erase and overprint primary zonations are limited to the grain margin and permeable regions within the grain core. Secondary zonations formed via two processes: (a) grain dissolution followed by overgrowth, and (b) remobilization of metals during oxidizing fluid flow events. In both instances, Ni and Co have been mobilized and concentrated, and are not lost to the hydrothermal fluid. Superimposed on these features is evidence of grain scale deformation related to periods of fault movement along the detachment surface. Sulfur isotope ratios (δ34S) in pyrite systematically decrease from the grain margin to the grain core, indicating that increased amounts of sulfur were derived from thermochemical sulfate reduction of seawater. Thus, pyrite records the evolution of fluid flow and deformation events during exhumation along the detachment surface from ∼1 to 2 km below the seafloor at the base of the lava pile, with temporal fluctuations in fluid redox identified as an important process in controlling Ni and Co enrichment in pyrite. 
PY 2024
PD JAN
SO Geochemistry Geophysics Geosystems
SN 1525-2027
PU American Geophysical Union (AGU)
VL 25
IS 1
UT 001136499200001
DI 10.1029/2023GC011033
ID 98128
ER

EF