Structural characterization of the internal domain of Paraguai Belt, in the Cangas region, south central portion of Mato Grosso, Brazil

Abstract

The structural study of rocks in the district of Cangas showed the identification of three phases of deformation for the Cuiabá Group in this region. The main structure oriented 120/27 is related to the first phase of deformation defined by a slate cleavage, parallel to the bedding and to the axial plane of recumbent folds. In the early stages of this phase a family of quartz veins (V1) was generated, arranged parallel to the structures of this phase of deformation, being all almost deformed. The second phase of deformation formed a crenulation cleavage (Sn+1), axial plane of opened to gentle and asymmetric normal folds, with preferential orientation 110/68. The third phase of deformation is represented by a set of centimetric to decametric scale fractures and faults with metric slip that cut all previous structures, with orientations 35/82. Related to this phase of deformation occurs a second family of quartz veins (V2), which fills the fractures related to Dn+2 and may or may not be carrying gold mineralization.