Morphometric analysis in neotectonis: the Campos do Jordão Plateau SP

Abstract

Morphometric maps and digital terrain models were created, using geoprocessing techniques, to assist neotectonic analyses in the Campos do Jordão Plateau. Digital terrain models permitted a general overview of the topography, highlighting the several topographic levels and the main morphological features, besides constituting the basis for morphometric parameters. Shadowed relief and slope orientation maps helped in the identification of morphostructural lineaments, complementing remote sensing data analysis. Morphostructural lineament analyses permitted the identification of the following trends: NE-SW/ENE-WSW, coherent with the regional Precambrian structures, and N-S/W-SE which reflect more recent structures. These lineament trends correspond to reactivation faults with normal and strike-slip components, related to different neotectonic stress regimes. Morphometric maps, in addition to structural analyses, revealeda tectonic contro lin the drainage network organization and compartimentalization of the plateau. The spatial distribution of drainage density, relief roughness, hydraulic gradients and isobase surfaces permitted the subdivision of the plateau into smaller blocks, delimited by the main trends of morphostructural lineaments. The techniques proved to be appropriate for the preliminary identification of anomalous areas that can indicate neotectonic control and can also be used in areas of sparce geological and geomorphological data.