The Paraguay Belt, located in the southeast border of the Amazon Craton records important events of the geological evolution of the planet at the end of the Precambrian era. The Paraguay Belt comprises neoproterozoic metassedimentary rocks of the Cuiaba Group, overlaid unconformably by ediacaran sediments of the Paraguay Basin, which includes glacial pelites and diamictites (Puga Formation), carbonates (Araras Group) and siliciclastic rocks (Alto Paraguay Group) heterogeneously deformed. The Paraguay Belt is a neoproterozoic orogen produced by the collision of the Amazon, São Francisco and Rio de La Plata cratons. The collision took place during the Brasiliana/Pan-Africana (600-520 Ma) and Paraguay (540-490 Ma) orogenies. This research presents field based structural data from the region of Nobres that suggests a tectonic history, which explains the stratigraphy and the geometry of the studied rocks based on a model of partitioned transpression. The transpressive deformation that affected the rocks in the region is late in relation to an early colisional event classicaly describe in the belt, evidenced by: (1) the uniform pattern of deformation displayed by all studied rocks that show non-cylindrical, forced folds forming antiform-synform arrays with no vergence; (2) the distinct domains of deformation heterogeneously distributed into weakly deformed areas separated by steep dipping strike-slip faults from areas of strongly deformed rocks that show steep dipping bedding (60-85°). The bedding in strongly deformed sedimentary rocks is geometrically concordant with the foliated fabric observed in the rocks from the Cuiaba Group. This relationship suggests that the deformation that affected the sedimentary rocks of the Paraguay Basin was controlled by the early ductile fabric in the basement rocks of the Cuiaba Group. The ductile fabric was reactivated during late regional transpression and controlled the development of zones where strain was preferentially accumulated. The observed of steep dipping bedding (> 50°) and the absence of collisional structures are incompatible with the presence of thrust fault in the studied region. These observations together with the stratigraphic pattern of the sedimentary sequences of the Paraguay Basin are incompatible with the characteristics of a foreland basin. This is supported by the following evidence: (1) the absence of angular unconformities; (2) the platformal nature of the ediacaran sediments; and (3) the heterogenous geographical distributions of the lithological units in the studied regions. Thus, the sedimentary rocks of the Paraguay Basin are interpreted as a neoproterozoic-cambrian sequence deformed during a eo-paleozoic late, brittle, transpressive deformation resulting from the reactivation of early ductile fabric in the basement. It is suggested that the rocks of the Cuiaba Group, represent the Paraguay Belt, the basement for the Paraguay Basin.
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