Geochemistry, mineralogy and genesis of Antimony mineralization in Choopan area, South Khorasan

Abstract

Choopan antimony deposit is located in the North of Lout desert, Central Iran. This area contains volcanic rocks of Early Tertiary, which are important for Sb, Pb & Zn, Ag, As, Cu and Au. Gold is below detection limit in major of these rocks. The main rocks in this area are volcanic rocks that have composite of toleoithic type, with dacite and andesite rocks. The main minerals are stibiconite, stetefeldite, bindehimite, galena, sphalerite, pyrite, arsenopyrite, sinabar, pyrolusite and chalcopyrite. The country rock in veins is dacitic porphyry rocks. The mineralization is associated by pervasive alteration of sericitization, argillitization, silicification, carbonization and propylitization. The alterations and mineralization are accompanied by faults directions, which seem to be main sources for hydrothermal circulation in these rocks. During the study 77 samples were analyzed for Cu, Pb, Zn, Au, and Ag, As, Sb, Hg, Cd and MO by AAS. Data processing showed that the Sb anomaly was developed mainly over the north and southeast area. The average of Sb content is about 4000ppm. There are good correlation between Sb and Pb and Ag. Geological, petrological, mineralogical, geochemical and fluid inclusion studies showed that the Sb mineralization in the Choopan area is a new epithermal type Antimony namely Supergen Adularia – Sericite or Sulphid Antimony – silver type.