FN Archimer Export Format
PT J
TI Preservation of Hydrothermal Fluid Copper Isotope Signatures in Chalcopyrite‐Rich Chimneys: A Case Study From the PACMANUS Vent Field, Manus Basin
BT 
AF Samin, Apolline
   Roerdink, Desiree L.
   Reeves, Eoghan P.
   Scheffler, Johannes
   Bach, Wolfgang
   Beinlich, Andreas
   Jamieson, John W.
   Rouxel, Olivier
AS 1:1;2:1;3:1,2;4:1;5:2;6:1,3;7:4;8:5;
FF 1:;2:;3:;4:;5:;6:;7:;8:PDG-REM-GEOOCEAN-CYBER;
C1 Department of Earth Science and Centre for Deep Sea Research University of Bergen Bergen ,Norway
   MARUM‐Center for Marine Environmental Sciences & Department of Geosciences University of Bremen Bremen ,Germany
   Institute of Geological Sciences Freie Universität Berlin Berlin, Germany
   Department of Earth Science Memorial University of Newfoundland St. John's NL, Canada
   Department of Marine Geosciences IFREMER Plouzané, France
C2 UNIV BERGEN, NORWAY
   UNIV BREMEN MARUM, GERMANY
   UNIV BERLIN, GERMANY
   UNIV MEM NEWFOUNDLAND, CANADA
   IFREMER, FRANCE
SI BREST
SE PDG-REM-GEOOCEAN-CYBER
UM GEO-OCEAN
IN WOS Ifremer UMR
   DOAJ
   copubli-europe
   copubli-int-hors-europe
IF 3.5
TC 0
UR https://archimer.ifremer.fr/doc/00876/98775/108422.pdf
   https://archimer.ifremer.fr/doc/00876/98775/108423.docx
LA English
DT Article
DE ;seafloor hydrothermal systems;copper isotopes;black smoker;chalcopyrite-rich chimney
AB Copper isotopes (δ65Cu) in hydrothermal fluids have the potential to provide information on ore‐forming processes occurring below the seafloor, but Cu isotope data from high‐temperature fluids are scarce. Here, we examine the extent to which coexisting sulfide minerals in a hydrothermal chimney can preserve fluid Cu isotope ratios using a fluid‐solid pair of a black smoker (333°C) from the Roman Ruins vent area (PACMANUS) in the Manus Basin. Two ca. 3 cm long transects through the chalcopyrite‐rich chimney wall show an increase in δ65Cu from 0.48 to 2.28‰ from the interior to the exterior, coupled with limited variation in sulfide δ34S (1.52–4.72‰). The Cu isotopic composition of chalcopyrite from the innermost wall closely resembles the δ65Cu value of the paired hydrothermal fluid, indicating that chalcopyrite in the inner ∼5 mm of the chimney records the Cu isotope ratio of the venting fluid. Beyond this, an increase in sulfide δ65Cu toward the exterior correlates with an increase in the relative abundance of secondary Cu sulfides. The appearance of bornite coincides with the presence of small barite crystals, suggesting this represents a redox gradient between reduced hydrothermal fluids and oxidized seawater admixing inwards. Elevated δ65Cu in this zone can be explained by the precipitation of secondary Cu sulfides from 65Cu‐enriched fluids formed during oxidative chalcopyrite dissolution. Our findings indicate that interactions with oxidizing seawater shift chalcopyrite δ65Cu values over small spatial scales, and that caution must be applied if chimney sulfides are used to reconstruct δ65Cu values of high‐temperature hydrothermal fluids. 
PY 2024
PD FEB
SO Geochemistry Geophysics Geosystems
SN 1525-2027
PU American Geophysical Union (AGU)
VL 25
IS 2
UT 001157273900001
DI 10.1029/2023GC011349
ID 98775
ER

EF