Estudo da cobertura pedológica e sua relação com a formação e evolução de depressões no sudoeste de Macaraí (SP)

Abstract

This research investigates the pedological cover to understand genetic processes at work in the formation and evolution of closed depressions in the Três Cantos compartment. The study area is located in the municipality Maracaí-SP (Brazil), at the interfluve between Anhumas and Capivara rivers, both tributaries of the Paranapanema River. The area has closed depressions in the top of local surface, with red-yellow and red soils and iron crust. To achieve our goal we evaluated two toposequences in the Mandacaru depression, as well as regional and local factors that could contribute to the formation and evolution of depressions. The procedures adopted for this research were based on the Structural Analysis of the Pedologic Coverage, proposed by Boulet et al. (1982). The results showed that the pedological processes that dominate are latosolization, hydromorphy and illuviation. The latosolization transforms the iron crust into Latosol in the Brazilian System of Soil Classification (Ferrasols-FAO, 2006). The hydromorphy that attacks the iron crust and Bw horizonsresulting in a block structure when dry, and massive when wetcombined with the illuviation process that transforms the horizons A and Bt into E result in Argisol in the Brazilian System of Soil Classification (Lixisols-FAO, 2006). The latosolization process was the first to transform the iron crust, followed by wet conditions, transforming the iron crust and latosols due to hydromorphy action; consequently, the plateau was deformed. Hydromorphy, therefore, was responsible for initiating depression formation and subsequently the illuviation process contributed to it. Currently these two processes act deepening and widening the depressions. The formation of depressions is related to the geological structure, and these depressions are the initial stage of the area's drainage system, as may be observed in areas where the depressions have been opened, and where the soils are not yet adjusted to the new form of the slope.

1978 – 2018, Os 40 anos da primeira experiência de aplicação da cartografia geomorfológica francesa de detalhe na zona tropical úmida brasileira: histórico, princípios da legenda, mudanças e sua difusão no país

“…Porém, desde o final dos anos 90 e, principalmente, início dos anos 2000, os mapas morfológicos e morfográficos têm sido largamente utilizados em estudos que trabalharam na relação pedogênese-morfogênese (FURQUIM 1997;NAKASHIMA 1999;PINHEIRO 2004PINHEIRO , 2009ARANHA 2011;BEATO 2012;BARREIROS 2013;GRIGOROWITSCHS 2013;NAKASHIMA 2013;ALVES 2014), dentre eles o Mapa da Cobertura Pedológica e Formas de Relevo do Alto Estrutural do Pau D'Alho (1:25.000), apresentado de forma inédita neste número da Revista do IG.…”

Distribuição Espacial De Depressões Na Bacia Do Alto Rio Preto (Go, Df, Mg) E Suas Relações Com Controles Geológicos E Pedogeomorfológicos

“…Assim, Queiroz Neto (2010), Espindola (2010), Alves et al (2014) e Alves (2015) conceberam que tais feições são originadas após uma fase de intensa pedogênese. Coelho Neto (1993) e Paisani et al (2006) demonstraram haver correspondência entre os lineamentosdos eixos de depressões e cabeceiras de drenagem com os de estruturas geológicas e da hidrografi a, sugerindo possível vínculo entre eles.…”