Between 2000-2001, new outcrops of convolute folds have been discovered at the Highway D. Pedro I, in the interconnection with the Campinas to Moji-Mirim and Moji-Guaçu Highway. The features are typical atectonic folds. A level of weathered laminated siltites exhibits tight to isoclinal folds in rocks of the Itararé Subgroup (Tubarão Group). Open folds in sandstones and siltites have also been displayed, but soon later they were destroyed. This paper sinthezises distinctive criteria for atectonic structures and describes similar features elsewhere. Two main alternatives for the origin of the deformations are considered: direct action of ice movements or gravitational dislocations of unconfined inconsolidated layers. Data integration indicates that the two types of occurrences at Campinas result of both processes, but the later mechanism explains better the described convolute folds.
