| Autor: |
Vearncombe, S., Barley, M.E., Groves, D.I., McNaughton, N.J., Mikucki, E.J., Vearncombe, J.R. |
| Zdroj: |
Journal of the Geological Society; August 1995, Vol. 152 Issue: 4 p587-590, 4p |
| Abstrakt: |
Early Archaean (3.26 Ga) volcanogenic massive sulphide (VMS) deposits located within the low strain and very-low metamorphic grade Strelley greenstone belt, East Pilbara, Western Australia, contain exceptionally well-preserved sulphide textures which are directly analogous to those formed in black smoker chimneys at present-day submarine hydrothermal vents. The VMS deposits are associated with seafloor alteration zones in and below silicacarbonate laminites, at the top of a pile of tholeiitic to calc-alkaline intermediate and felsic volcanic rocks with trace element abundances indicative of modern subduction-related processes. VMS mineralization comprises Zn-rich sulphide lenses with significant Cu and barite, and variable Pb and Ag, above Cu-rich stringer zones, all of which are similar to Phanerozoic VMS deposits. Sulphide-sulphate mineralization implicates hydrothermal discharge into sulphate-bearing ocean waters. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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