Gold deposits in poly-deformed metasedimentary rocks: 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, Dn, and Dn+1. Phases Dn-1 and Dn have a direct relation to the mineralization, and mineralized quartz veins are parallel to the Sn foliation (S0 //Sn-1 //Sn ). The intersection between the S0//Sn-1 bedding and the Sn foliation generates an intersection lineation parallel to the Dn fold axis, plunging to the NW, which has favored an increase in the volume of mineralized bodies.