Gênese do relevo entre a Serra da Fartura e rio Chapecó - Planalto das Araucárias: o caso da superfície geomorfológica de Abelardo Luz (SC)

Abstract

This dissertation seeks to understand the evolution of landforms in the sector between Fartura Mountain and the River Chapecó (Abelardo Luz - SC), located on the geomorphological surface of Abelardo Luz, Plateau of Araucárias. Therefore it follows two research fronts: the characterization of the materials that make up the superficial formation representative of the area and fluvial-morphometric analysis of the current drainage. To achieve the objective of the research analysis in the field, in the laboratory and in the cabinet were carried out. In the field description was identified the horizons of superficial formation through color, texture, structure and consistency. In laboratory granulometric, routine chemistry, particle density, analytical chemistry (10 leading oxide), iron content (free, total, amorphous) and mineralogy by X-ray diffraction analyzes were performed. The superficial formation is ten meters thick, and of these, six meters and half are exposed in roadblock and three and a half meters were described by manual probing with Dutch auger. The horizons have been identified: Ap (0-30 cm); AB (30 - 70 cm); BA (70 - 140 cm); Bw1 (140-420 cm); Bw2 (420-700 cm); BC (700-860 cm); CB (860-950 cm) and C (950-1000 cm). Through the physical and chemical routine characteristics, the solum may be classified as Oxisoil, aluminum character. The routine chemical analysis shows that there is not an increasing order of basic cations in depth, thus showing to be an allochthonous soil, in the most superficial part (up to about 6m). The chemical analysis confirms the routine chemistry data, demonstrating that not increasing order of depth basis. The Ki and Kr values attest well weathered formation from the base, indicating again allochthonous material in the superficial part and autochthonous in the base. Data from iron analyzes by Fed-Feo / Fet reason show that the weathering of the superficial formation is evolved. Mineralogical by X-rays showed mineral quartz type, hematite, magnetite, gibbsite, anatase, cristobalite and goethite and clay minerals of the kaolinite and vermiculite and / or chlorite type. The presence of gibbsite in any Solum, indicates that there is partial desilicatization (monosialitization) up to a total desilicatization (alitização). The fluvio-morphometric analysis of drainage indicates movement blocks in the study area, and the Serra da Fartura is characterized as a rising block. Subsident block is found from this point up to the channel of river Chapecó. Finally, the analysis results indicate the occurrence of overlap of models etchplanation and pediplanation and that the superficial formation has more than one polygenetic genesis in the study area.