Fatores e processos envolvidos no desenvolvimento de formas cársticas em rochas siliciclásticas em Minas Gerais, Brasil

Abstract

Karstic features developed in rocks poor in calcium carbonate have more recently called the attention of researchers. That is the case of the siliciclastic rocks not included among those in which karst can develop because of its low rates of solubility. However, researches in areas of quartzite and sandstones revealed the occurrence of relief forms which were until recently reported as occurring only in geological subs tract prone to chemical dissolution. This research aims to present and discuss the factors involved in the elaboration of such landforms in Itambé do Mato Dentro, Espinhaço Meridional, Minas Gerais State, Brazil. Methodological procedures based on quantitative as well as qualitative evaluation of these factors were used to provide a basis for comparing them with those pointed out by the literature as the most representative ones for cave evolution as for instance the hydraulic gradient. Results show that in the study area this factor has not the importance attributed to it by literature for the development of karstic features elsewhere. Analysis also indicates that the main factor involved in the evolution of the karstic forms is the lithology which seems to be responsible for the acceleration of chemical as well as mechanical weathering