Geochemistry and crystallochemistry of oceanic hydrothermal manganese oxyhydroxides showing Mn-Cu association

Journal Article · Sat Apr 01 00:00:00 EST 1989 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(89)90029-X· OSTI ID:5127150

Stouff, P; Boulegue, J ^[1]

---

1. Universite Pierre et Marie Curie, Paris (France)

Hydrothermal iron and manganese oxides have been found in association with sulfides dredged on the E.P.R. near 7{degree}N. The Mn phase, mainly a 10-7 {angstrom} phyllomanganate, presents a very important enrichment in Cu (up to 30% as weight of oxide). The Fe phase, mainly hydro-goethite, has a very low content of metals of economic interest. Also Mn-Cu oxide particles have been collected in sediment traps near the hydrothermal vents at 13{degree}N. Using the Mn oxide samples of 7{degree}N, Cu shows two simultaneous oxidation states: +I and +II (ESCA and XAS edge measurements). Cu is adsorbed on the Mn(O,OH){sub 2} layers and partially belongs to the water layers (EXAFS results). This seems to be the first report of naturally occurring Cu-buserite in this environment. Lead isotope abundances, the presence of Cu(I), thermodynamic considerations on the stability of the Mn-Cu oxyhydroxides and unsuccessful attempts made with synthetic 10-7 {angstrom} phyllomanganates (buserite and birnessite types) at low temperature in order to stabilize Cu(I) and incorporate it in the interlamellar space of the manganate, lead the authors to accept a high temperature origin for the formation of the Mn-Cu oxyhydroxides. They present a transport model for Cu and Mn precipitation from oceanic hydrothermal fluid, to explain the formation of Mn-Cu oxyhydroxides.

• OSTI ID: 5127150
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Vol. 53:4; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
MANGANESE HYDROXIDES
ENVIRONMENTAL TRANSPORT
HYDROTHERMAL SYNTHESIS
PRECIPITATION
STRUCTURAL CHEMICAL ANALYSIS
MANGANESE ORES
CHEMICAL COMPOSITION
COPPER COMPOUNDS
CRYSTALLOGRAPHY
ELEMENT ABUNDANCE
GEOCHEMISTRY
GOETHITE
HYDROTHERMAL SYSTEMS
LEAD ISOTOPES
OFFSHORE SITES
SEAS
SEDIMENTS
X-RAY SPECTROSCOPY
ABUNDANCE
CHEMISTRY
ENERGY SYSTEMS
GEOTHERMAL SYSTEMS
HYDROGEN COMPOUNDS
HYDROXIDES
ISOTOPES
MANGANESE COMPOUNDS
MASS TRANSFER
MINERALS
ORES
OXIDE MINERALS
OXYGEN COMPOUNDS
SEPARATION PROCESSES
SPECTROSCOPY
SURFACE WATERS
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
580000* - Geosciences