Zonation of supergene minerals is most prominently developed in...

Zonation of supergene minerals is most prominently developed in a vertical sense with respect to the weathered paleosurface. A basic weathering pro le for VMS deposits contains four zones from the original ground surface down- ward: (1) a leached capping dominated by Fe oxides, clay minerals, and quartz, (2) an oxidized zone dominated by secondary sulfates, (3) the supergene enrichment zone with abundant chalcocite and other Cu-rich sul des, and (4) the
top of the underlying massive sul de protore. More complex zonation patterns are evident in mature supergene pro les developed on VMS deposits, especially deposits rich in Zn, Pb, and As (table 12–1). The thicknesses of individual zones are highly variable and increase toward margins of mas-sive sul de bodies and along structural features crosscutting protore.