dc.contributor.author
Samin, Apolline
dc.contributor.author
Roerdink, Desiree L.
dc.contributor.author
Reeves, Eoghan P.
dc.contributor.author
Scheffler, Johannes
dc.contributor.author
Bach, Wolfgang
dc.contributor.author
Beinlich, Andreas
dc.contributor.author
Jamieson, John W.
dc.contributor.author
Rouxel, Olivier
dc.date.accessioned
2024-03-19T09:33:43Z
dc.date.available
2024-03-19T09:33:43Z
dc.identifier.uri
https://refubium.fu-berlin.de/handle/fub188/42916
dc.identifier.uri
http://dx.doi.org/10.17169/refubium-42632
dc.description.abstract
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.
en
dc.format.extent
17 Seiten
dc.rights.uri
https://creativecommons.org/licenses/by/4.0/
dc.subject
seafloor hydrothermal systems
en
dc.subject
copper isotopes
en
dc.subject
black smoker
en
dc.subject
chalcopyrite-rich chimney
en
dc.subject.ddc
500 Naturwissenschaften und Mathematik::550 Geowissenschaften, Geologie::550 Geowissenschaften
dc.title
Preservation of Hydrothermal Fluid Copper Isotope Signatures in Chalcopyrite-Rich Chimneys: A Case Study From the PACMANUS Vent Field, Manus Basin
dc.type
Wissenschaftlicher Artikel
dcterms.bibliographicCitation.doi
10.1029/2023GC011349
dcterms.bibliographicCitation.journaltitle
Geochemistry, Geophysics, Geosystems
dcterms.bibliographicCitation.number
2
dcterms.bibliographicCitation.volume
25
dcterms.bibliographicCitation.url
https://doi.org/10.1029/2023GC011349
refubium.affiliation
Geowissenschaften
refubium.affiliation.other
Institut für Geologische Wissenschaften / Fachrichtung Geochemie, Hydrogeologie, Mineralogie
refubium.resourceType.isindependentpub
no
dcterms.accessRights.openaire
open access
dcterms.isPartOf.eissn
1525-2027
refubium.resourceType.provider
WoS-Alert