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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 modem subduction-related processes. VMS mineralization comprises Zn-rich sulphide lenses with significant Cu and barite, and variable Pb andAg, 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. Fig. 2. Textural zonation from a small fluid conduit zone showing the outward progression from pyrite-chalcopyrite (cp) colloform textures to pyritic (py) dendrites (branching to arborescent). Location: Kangaroo Caves. Scale bar = 2 mm.

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