Análise morfoestrutural aplicada ao lineamento transbrasiliano na região de Santana do Acaraú, Noroeste do Ceará.

Abstract

The study arca is located in the northwestem Ceará, near the town of Santana do Acaraú. It is 255 km far from Fortaleza City and lies within the geologic context of Borborema Province, ecompassing the geologic domains of Médio Coreau and Ceará Central. The litostratigraphy encompasses, from base to top, Granja Complex, Canindé and Independência units (Ceará Complex), São Joaquim and Covão formations (Martinópole Group), granitoids, Jaibaras Group, Ipu Formation (Serra Grande Group), Barreiras Formation and holocenic alluvium deposits. The goal of this study is the identification of geometry and kynematics of fracture groups in the regional scale, through the morphostructural analysis of drainage netwoks and infamiatios at outcrop scale. The applied methodology was based in the analysis of drainage networks extracted from a digital elevation model (SRTM) with a 30 m grid. Among several identified drainage patterns, the retangular pattern stands out, besides trelis, radial pattern and their variations, implying a tectonic control. The anomalies are mainly represented by lineaments and divides with the occurence of structural highs. Therefore this work revealed the importance of geoprocessing techniques in the caracterization and compartmentalisation of 18 diferent morphostructural domains, determined through drainage pattern analysis, drainage anomalies and their relationship with bedrock.