Deutsch
 
Datenschutzhinweis Impressum
  DetailsucheBrowse

Datensatz

DATENSATZ AKTIONENEXPORT

Freigegeben

Konferenzbeitrag

Strontium and sulfur isotopes reveal the complex evolution of the Sotiel-Migollas VMS deposit (Iberian Pyrite Belt)

Urheber*innen

Velasco-Acebes,  J.
External Organizations;

Tornos,  F.
External Organizations;

/persons/resource/abiel

Kidane,  A.
3.1 Inorganic and Isotope Geochemistry, 3.0 Geochemistry, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;

/persons/resource/michawi

Wiedenbeck,  Michael
3.1 Inorganic and Isotope Geochemistry, 3.0 Geochemistry, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;

Velasco,  F.
External Organizations;

Externe Ressourcen
Es sind keine externen Ressourcen hinterlegt
Volltexte (frei zugänglich)
Es sind keine frei zugänglichen Volltexte in GFZpublic verfügbar
Ergänzendes Material (frei zugänglich)
Es sind keine frei zugänglichen Ergänzenden Materialien verfügbar
Zitation

Velasco-Acebes, J., Tornos, F., Kidane, A., Wiedenbeck, M., Velasco, F. (2015): Strontium and sulfur isotopes reveal the complex evolution of the Sotiel-Migollas VMS deposit (Iberian Pyrite Belt), (Goldschmidt Abstracts), 25th Goldschmidt Conference (Prague, Czech 2015), 3252-3252.


Zitierlink: https://gfzpublic.gfz-potsdam.de/pubman/item/item_2253896
Zusammenfassung
The SIMS δ 34 S study of pyrite from the late Devonian shale - hosted volcanogenic massive sulfide deposit of Sotiel - Migollas (Iberian Pyrite Belt) combined with the 87Sr / 86Sr ratio of the intergrown carbonates [1] track the complex evolution of the seafloor hydrothermal system. SIMS δ 34 S of pyrite showing different textures exhibit a wide range in values from - 35.8±4.6‰ in the primary framboidal morphologies to - 0.9±1.3‰ in the late recrystallized euhedral crystals. The 87 Sr/ 86 Sr ratios vary between 0.70846 and 0.70983, being the less radiogenic values close to those of the coeval seawater, estimated by [2] in the 0.70750 - 0.70850 range. There is a strong linear correlation between these two isotope systems, with the most negative δ 34 S values of the pyrite being intergrown with carbonates with the lowest 87 Sr/ 86 Sr ratios. Extremely 34 S - depleted values can only be interpreted as reflecting the biogenic reduction of the seawater sulfate with a large isotopic fractionation in an open system [3]. This is consistent with a strontium seawater signature, suggesting that these samples correspond to the external parts of the exhalative system in contact with seawater and with bacterial sulfate reduction taking place on the seawater - massive sulfides interface. In contrast, the other endmember is interpreted as reflecting the late maturation of the system inside the ore lens with input of deep sulfur - likely derived from TSR processes or leached from the basement - accompanied by 87 Sr - enriched fluids. We propose a model for the growth of biogenic mounds on the seafloor with alternating carbonate - sulfide bands that were gradually buried by subsequent growth. The isotope signatures changed due to the later maturation of mound and the input of deep hydrothermal fluids.