GEOMORFOLOGIA DO CAMPO DE INSELBERGUES DE QUIXADÁ, NORDESTE DO BRASIL

RUBSON PINHEIRO MAIA; MARCOS ANTONIO LEITE DO NASCIMENTO; FRANCISCO HILARIO BEZERRA; HENRIQUE SAMPAIO DE CASTRO; ANTÔNIO JEOVAH DE ANDRADE MEIRELES; LUIS MARTIN ROTHIS

Revista Brasileira de Geomorfologia

Uniao da Geomorfologia Brasileira

Lugar: Sao Pablo; Año: 2015 vol. 16 p. 239 - 253

2236-5664

In the north part of the Borborema Massif, Northeast Brazil, various fi elds of inselbergs characterize the hinterlanddepressions. These reliefs occur in areas of granitic intrusions that have been exhumed by differential erosion. InQuixadá, State of Ceará, lies one of the most representative fi elds of inselbergs. This fi eld is composed of variousgenerally concave-convex, fractured rock masses, formed by subaerial exposure of a granite batholith. In this work,the various forms of inselbergs were classifi ed according to their morphological patterns. These patterns werecorrelated with granite fácies and fracture density. We observe that fácies rich in porphyritic feldspar phenocrystalsoriginated inselbergs with dissolution features of fl ute and vasques types, while those characterized by the presenceof dikes and mafi c enclaves formed inselbergs characterized by collapse taffonis. This correlation allowed us toconclude that even within the same geologic granitoid unit, internal fácies variations may result in different featuresaccording to the mineralogical textural and fracturing characteristics of the bedrock.