Some Characteristics of the Oxidation Zone of Sulfide Ore Deposits in Lower Yangtze Area, Southeast China

Abstract

The characteristics of supergene zoning and processes of oxidation of disulfide-rich ore deposits in Lower Yangtze area, Southeast China, are representative to the warm and humid area in medium latitude zone. The distinguishing features are (1) limonite^*1 gossans extended to a great depth due to the slow uplift of the area during the long process of oxidation; (2) the existence of a subzone of current secondary sulfide enrichment due to the rapid decomposition of Cu sulfide ore in the upper part, which makes Cu intensively migrating downward; (3) the assemblage of secondary native copper, cuprite and their further oxidized products, tenorite and malachite, is an evidence of the ever-existence of ancient secondary sulfide enrichment; (4) carbonate and silicate are the prominant oxidation products of Pb-Zn ore deposits.
The contrasts of the characteristics of sulfide ore oxidation in Lower Yangtze area to that of the arid Northwest China are also clarified in this paper.