Granite Weathering, Denudation Processes, and Associated Landforms in the Itu-Cabreúva Region, São Paulo, Brazil

Abstract

The Itu-Cabreúva region is located about 90 km northwest of the São Paulo city center. The geological setting is characterized by the expressive occurrence of Neoproterozoic granitic rocks. These intrusive rocks form large plutons that have given rise to flattened hills, valleys with concave-convex slopes, and superficial drainage systems. As part of this larger framework, several smaller landforms with unique appearances occur, which can be categorized into six groups: nubbin, boulder, balanced rock, castle koppie, cave, and minor form. Although these reliefs were formed under similar weathering conditions, the research results show that the physical properties of the lithology and the nature and density of the joints strongly influenced the shape and size of the blocks. These geoforms have exceptional scenic value and are situated in a geographically advantageous location for a range of educational and recreational activities that can be adapted to different levels of knowledge. The implementation of such proposals in the context of understanding the physical environment would result in a number of benefits, including (i) greater community involvement in the environment, (ii) valorization of the local landscape as a historical record of the planet's evolution, and (iii) improvement of urban geological risk prevention programs. Finally, these landforms are fascinating and offer conclusive evidence that can be observed on a wide range of scales, illustrating how the brittle deformation and magmatic fabric of the granite massifs influenced the development of the local landscape.