Soil differentiation in two toposequences developed from basaltic rocks in North-Central region of the Paraná State, Brazil

Abstract

In regions where there were basaltic rocks formation due to magmatic flows, variation in particle sizes and rock composition determine characteristic reliefs influencing chemical and physical attributes. The aim of the article was to characterize two different toposequences over basaltic rock basis, in order to identify the influence of their variation in soil formation, morphological properties and their distribution along the slope. The study was carried out in the Third Plateau of Parana State, Brazil, at Serra Geral geological formation, There were chosen two toposequences in equidistant 2000m parallel transects in southwest-northeast direction with different relief and rock composition and features. It was named undulated relief slope (VRO) and gently undulated relief slope (VSO) in which there were carried out profile morphological description with soil classes identifying, chemical analysis and clay mineralogical analysis. The results permitted to conclude that the internal dynamic and the magmatic segregation process were responsible for relief shapes and rock types formed with significant variation in soil types according variation in composition in the same rock, Both relief shapes and basalt differentiation had strong influence in soil evolution level and soil type distribution along the slopes with distinct B horizons, Nitic B and Latosolic B.