SOLOS VERMELHOS E AMARELOS COESOS DE TABULEIROS COSTEIROS: GÊNESE, EVOLUÇÃO E INFLUÊNCIA DA NEOTECTÔNICA

Abstract

The Coastal Tablelands is a geomorphological unit developed on the Barreiras Group, which has a large area and soils that support various productive activities, such as forestry and citrus. The soils of the Coastal Tablelands present physical and chemical limitations poorly understood, which further justify the need for genetic studies. Therefore, we studied the origin and evolution of red and yellow soils across a toposequence on the northern coast of Bahia state, as well as mechanisms involved in the formation of cohesive horizons. We conclude that the red soils formed from muddy conglomeratic sandstones and muddy sandstones Barreiras Group and became yellow soils. The genesis of red soils was accompanied by the formation of cohesive horizons, which have become more hardened and thick with the evolution of soils to yellow, which occurred with a decrease in the levels of free iron, clay degradation of surface horizons and advancing argilluviation. The topossequence is currently undergoing a process of podzolization, due to the influence of neotectonics, responsible for the formation of a closed depression that accumulates water after rain episodes, creating a temporary hydromorphic environment and accentuating the clays degradation of the superficial horizons.