Peatlands evolution model of Serra do Espinhaço Meridional in a pedological, geomorphologic and geochemical approach

Abstract

The Serra do Espinhaço Meridional (SdEM) is composed mainly quartzite, phylites and metaconglomerate belonging to the Espinhaço Supergroup. In lowland of the landscape, mild climate, poor drainage and the existence of plant species adapted to such conditions favor the formation of peat bogs, characterized by high levels of organic matter. This ecosystem is home to many endemic species and serves as an important archive of climate and vegetation changes, in addition to acting directly on the dynamics of water in the basin in which it is. This work proposes to study the evolution model of peatlands, based on the hypothesis that these originated in recent Quaternary in depressions formed on surfaces of flattening from the morphogenesis of relief on geological materials with different susceptibility to weathering and erosion. This difference of rock types, together with the condition of climate and topography generates differential erosion causing the quartzite outcrop in the landscape and serve as bedrock of low permeability and formation of an oligotrophic environment needed for the genesis of peatland. A representative area of SdEM was selected and the analysis of geological, geomorphologic and satellite images, current and buried (paleosols) representative will be selected and sampled. Dating will be conducted by LOE (sediment) and radiocarbon dating (O.M). To verify the influence of bedrock in the geochemistry of peat bog will be tracked the source material of sedimentation through of total chemical and mineralogical analysis of soil fraction. Will be analyzed interstitial water pH, electrical conductivity, dissolved cations and carbon. Intended generate an evolution model that helps to understand the key elements that make the region an environment favorable to formation of peatlands. (AU)