Contribuição aos estudos hidrogeológico e morfoestrutural na área de ocorrência das cavidades naturais da Serra Sul, Carajás-PA

Abstract

Speleological Carajás Unit have cavities generated by dissolution process / degradation of iron formation / lateritic and associated rocks; this way, research on hydrogeological and morphostructural focus supporting a geo-speleological diagnosis of cavities and speleothems area, since genesis of these cavities is mainly related to water action, which operates as the main weathering agent on the rocks. Data acquired such as, location, observation, classification and interpretation, as well as analysis of genesis and development processes of geological environment in which these cavities are found, there was a record of hydrogeological and landscape features in vicinity of the same occurrence. Information extracted, integrated with other lines of research, give focus to the knowledge of evolutionary history of cavities contained in the region and, above all, the associated speleothems. It was necessary primarily, an understanding on a regional scale of study area, with a special focus on structuring the area, since, for the study of metavolcanic rocks that occur in Carajás, a clear understanding with regard was necessary the behavior of fracture systems; this way, hydrogeological study, had a broad conceptual and methodological support to structural geology. To perform such an analysis was used Photointerpretation method of sensing images and specific software used in the preparation of maps, such as drainage and relief, structural alignments and strain ellipsoid. Only at a later stage, there was a micro systematic analysis of the area, achieved through specific data relating to natural cavities in the area, such as altimetry, tectonic structures, lithology and hydrological features, and other intrinsic characteristics of these cavities. Information obtained was added to rainfall analysis of the area. This amount offer understanding of a genesis model of these cavities and associated speleothems.