Gold deposits in poly-deformed metasedimentary rocs: a case study of the C1-Santaluz gold deposit, Itapicuru Greenstone Belt, Northeast of Brazil

Abstract

The C1-Santaluz gold deposit is located in the Itapicuru greenstone belt in Bahia State, Brazil. Metavolcanic and metasedimentary rocks dominate at the base and top, respectively. The ore minerals related to the auriferous mineralization are pyrite, arsenopyrite, sphalerite, chalcopyrite and stibnite. Arsenopyrite is related to, and associated with the presence of gold in quartz veins, a feature which is detected by scanning electron microscope analyses. The deposit is structurally complex, with tree deformational phases being recognized: Dn-1, D-n, and Dn+1. Phases Dn-1 and D-n have a direct relation to the mineralization, and mineralized quartz veins are parallel to the S-n foliation (S-0//Sn-1//S-n). The intersection between the S-0//Sn-1 bedding and the S-n foliation generates an intersection lineation parallel to the D-n fold axis, plunging to the NW, which has favored an increase in the volume of mineralized bodies.