Caracterização geomorfológica dos preenchimentos sedimentares em marmitas de dissolução no maciço da Serra da Baixa Verde PB/PE

Abstract

It is necessary to develop research that can understand the geomorphological processes that operate over time, in a perspective of landscape reconstruction. The present dissertation has as its object of study the Dissolution Weathering pits and their sedimentary fillings, centred on the slopes and plateaus with altitudes above 700 m, in the residual massif of Serra da Baixa Verde (PB-PE). The guiding principle of the research was that the geomorphological features worked on here, seasonally flooded, their genesis is associated with chemical weathering that works overtime, under dry climates conditions (semiarid and sub-humid). Thus, the central objective was to characterize the geomorphological scenario of these geomorphological features. Therefore, the first step was the identification, mapping and morphological characterization with the aid of Unmanned Aerial Vehicle (UAV), as well as the morphological classification based on Gutiérrez (2005) and Silva, Correa and Amorim (2017). The sedimentological and morpho-stratigraphic data allowed to understand the evolutionary chain of the sedimentary fillings. The geochemical analysis, in turn, using the X-Ray Fluorescence Spectrometry (FRX) technique, showed the degree of sediment change, through the Ki and Kr indices, in addition to the chemical composition, which is in line with the lithology local. The data indicated that the sediments are of a character in situ, and geochemically little ripened, with a high concentration of silica, aluminium, iron and potassium. Oxides considered polluting were also identified, such as Diphosphorus Pentoxide (P2O5) and Sulfur Trioxide (SO2). The characteristics of the sediments, such as granulometry, their chemical nature and stratigraphic arrangement provided data from past processes. They are indicating that the landscape morphology emerges from the intertwined links between lithology, soils, climate, weathering resistance, among others. Therefore, this research collaborates with the understanding of the evolution of Dissolution Lunchboxes in the semiarid region of Northeast Brazil.