Avaliação e comparação das taxas de erosão química e mecânica entre arenitos e argilitos: implicações na evolução geomorfológica da bacia do Rio Corumbataí (SP)

• Autor(a) principal: Spatti Junior, Eder Paulo [UNESP]
• Data de Publicação: 2015
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/136650; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/09-03-2016/000858143.pdf
• topic: Geomorphology; Geomorfologia; Intemperismo; Erosão; Arenito; Argilito; Corumbataí, Rio, Bacia (SP)

The chemical and mechanical erosion rates are essential elements in understanding the evolution geomorphological. Of these processes result in products that are the basis for the development of human activities, especially in the conditions of land use. In this work were evaluated chemical and mechanical erosion rates and their implications for geomorphological evolution of the Corumbataí river basin, São Paulo State, Brazil (SP). For this, two sub-basins were chosen sandy lithological composition (Botucatu and Pirambóia formations) and clay (Corumbataí Formation), ie the basins of the streams Monjolo Grande and Jacutinga, respectively. The chemical erosion rates It was determined by the specific hydrochemical flow of cations, anions and silica (river water), with the respective correction of atmospheric inputs and the density of the rocks obtained a value of 1.73 m / Ma to sandstones and 0.76 m / Ma to mudstones. The weathering processes responsible for the alteration of rocks in both basins tend to monosialitization with the formation of mineral 1: 1, as kaolinite. The weathering processes are also responsible for the consumption of CO2 in the soil / atmosphere interface and the values obtained were 0.37 x 106 mol / km2 / year and 0.45 x 106 mol / km2 / year to sandstones and mudstones respectively. The mechanical erosion rates were calculated by the specific flow of silt in suspension and had obtained a value of 14,20m / Ma for sandstones and 11,66 m / mA for mudstones. The difference in the change speeds of rock and removal of surface horizons leads to denudation of imbalance, with a much stronger component perpendicular to the parallel component in 12,7 m / Ma and 10,84 m / Ma in sandstones and mudstones. Taking into account the theory of dynamic equilibrium is possible to say (based on mechanical erosion of values) that the lowering of the topography does not occur proportionally in sandstones and mudstones