Geochronology of veredas and campos de murundus environments of the Uberlândia-Uberaba plateau: subsidies to evolution of the landscape

Author(s)

Vinícius Borges Moreira

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Geociências
• Defense date: 2017-02-03

Examining board members

Archimedes Perez Filho; Raul Reis Amorim; Cenira Maria Lupinacci da Cunha

• Advisor: Archimedes Perez Filho

Abstract

In the region of the Triângulo Mineiro - MG there are extensive and continuous plateau of planed surface, which are presented in a staggered way, separated by inland fluvial valleys. Among these, the Uberlândia-Uberaba plateau, the subject area of this dissertation, stands out. On the plateau there are veredas and campos de murundus that consist of subsystems typical of the Brazilian Cerrado, commonly associated to drainage network and tabular relief, understood here, as key environments in the Holocene paleoenvironmental interpretation. In order to characterize and understand the processes of formation of these environments, and their evolution in the landscape, associating them with Holocene climatic pulses, some fundamental methodologies and techniques were proposed in geomorphological analysis. Application of morphometric indices in the drainage network and associated basins, elaboration of topomorphological profiles, chemical-physical characterization of the surface cover material of the analyzed subsystems and absolute dating by OSL (Optically Stimulated Luminescence). From this context it is understood that Holocene climatic oscillations / pulsations provided environmental conditions for geochemical abatement, differential erosion and carving / widening of fluvial channels on the plateau, between hot / humid and hot / dry periods, providing ideal conditions for formation of veredas and campos de murundus. Paleoclimates altered the landscapes of the region of occurrence of the plateau, generating different stages of evolution, which can be identified through the techniques proposed here. The results of the morphometric analysis indicated that the campo de murundus and veredas occur in the incidence areas of the Cobertura Cenozoica and in the contact between the cover and the Formação Marilia respectively, being these strongly conditioned by the fluvial and pluvial dynamics. The texture found for the murundus was very clayey, indicating to be material of origin of Cobertura Cenozoica. The veredas obtained a result of average texture, corresponding to the material of arenitic origin of the Formação Marilia. The OSL confirmed that the veredas and campos de murundus are environments formed during the Holocene period, possibly in two distinct phases, 3,500 to 4,000 AP and 1,000 to 2,000 AP. Indicating at least five stages of evolution of the landscape that developed Mainly due to the influence of climatic pulses associated with regional physical aspects (AU)

• FAPESP's process: 15/10417-1 - Geochronology of veredas and campos de murundus environments on the Uberlândia - Uberaba plateau : implications for landscape development
• Grantee: Vinícius Borges Moreira
• Support Opportunities: Scholarships in Brazil - Master