Stratigraphic position and deformation tectonics of the Itaqueri Formation, central-eastern portion of the state of São Paulo

Abstract

The Itaqueri Formation, in its type-area, comprises rudaceous deposits of alluvial fans covering the serras of Itaqueri, São Pedra, São Carlos and Cuscuzeiro, and its origin is related to the evolution of the Japi Planation Surface. A Paleocene-Eocene age is inferred from the age of alkaline rocks emplaced along the Rio Moji-Guaçu Lineament which caused hydrothermal silicification coeval with the sedimentation. Deformation tectonics of this unit is characterized by brittle structures, mainly faults and joints, related to movements along the Rio Tietê, São Carlos - Leme and Rio Moji-Guaçu Lineaments. The stress-field for these faults presents a horizontal NW-oriented σ1, a horizontal NE-oriented σ3, and a vertical σ2, compatible with a WNW to E-W right-lateral strike-slip binary ofprabable neotectonic (Quatemary) age