Análise estrutural do Granito Cerro da Cria, São Sepé – RS

Abstract

The Cerro da Cria Granite is located in the south of the municipality of São Sepé - RS, a region that is geologically included in the São Gabriel Terrain, that is part of the Sulrio-grandense Shield. The São Gabriel Terrain is one of the representatives of the orogeny of the Brazilian Cycle, so that the Cerro da Cria Granite is a representative of the last magmatic events of this orogeny, being thus characterized as post-collisional and being thus inserted within the Saibro Intrusive Suite. One of the characteristics of the post-collisional environment is the development of large transcurrent faults and one of the main characteristics of Cerro da Cria Granite is the transcurrent fault zone that intersects and causes a brittle deformational regime, with development of joints, fractures and filled veins with quartz. In the surrounding of the region, the Cerro da Cria Granite intrudes metamorphic rocks from the Bossoroca Complex, which in the study area is represented by the Campestre Sequence and Arroio Lajeadinho Sequence, where within these sequences there are occurrences of gold mineralizations, discovered since the 70th years. The present project uses, for the study of the deformation in Cerro da Cria Granite, remote sensing tools, such as: Google Earth images; Landsat-8 images; digital elevation models and shaded relief maps. From the digitization tools of the local and regional scale guidelines. Subsequently, a structural analysis of Cerro da Cria Granite was performed, with data measured in the field. Thus, it was established that there are five families of fractures not Cerro da Cria Granite and granite was divided into three structural blocks. Finding that the structural block 3 had a translation to the northeast and Cerro da Cria Granite has two distinct deformational events.