Mapeamento geológico integrado 1:50.000 da região da Serra da Jiboia (GO) - área 1

Abstract

This paper presents the results obtained from the 1:50000 mapping of the Serra da Jiboia region. The detailing of the geological units was possible with the conciliation of bibliographical survey, photointerpretation, geophysical, geochemical, and geoenvironmental, lithological and structural data obtained in the field. As a result, the following mapped units were detailed in the context of the Brasília Belt brim and the Goiás Magmatic Arc (AMG): Anicuns-Itaberaí Metavolcanosedimentary Sequence (SAI), Campestre Gnaissic-Migmatitic Complex, Santa Bárbara Complex and the Creoulos Granodiorite. The SAI is characterized in forearc basin associated with an island arc system, recorded by platform sedimentation in the rhythmic-carbonate unit and marine regression depositional in the psamo-pelitic unit. The Creoulos granodiorite records syncolonal magmatism of meta to peraluminous granites. The geological evolution is marked in the Brasiliano, responsible for the opening of the Goiás Ocean and later the closure. This phase concludes the formation of island arcs and the Brasília orogen. The deformation of the rocks is represented by east-west compression that resulted in isoclinal thrust folds with N-S axis and eastward vergence with higher temperature and pressures. Conjugate fracture systems occur, with E-W and NE-SW direction that, by progressive deformation, originate NS, NW and NE transcurrent shear zones. The observed metamorphism of the rocks is a variation of high greenish schist to amphibolite facies, associated to SAI, besides hydrothermal metamorphism linked to shear zones. The area presents some economic aspects, with potential for manganese, calcitic marble and remineralizers for agriculture and gravel and sand for civil construction.