Estudo da geologia do cinturão de Lúrio, com especial realce à evolução geológico-estrutural da região de Lalaua - Malema, através do uso de imagens ASTER e SRTM

Abstract

This scientific project investigated the complex geological-structural evolution of an area located in the core of the Lúrio Belt (Lalaua and Malema Districts, Nampula), a zone of intense Pan-African shear with importance in the Regional Geology of Mozambique. The work applied and validated the integrated use of Remote Sensing data (ASTER and SRTM images) to unveil the architecture of the Earth's crust in areas that are difficult to access. Through rigorous processing (combination and ratio of ASTER bands for lithology; SRTM relief shadow images for structure), the study mapped and described the local geological-structural scenarios. The results obtained show that, in addition to confirming the gneissic units of the GTK CONSORTIUM 2006, new lithological units were distinguished, such as felsic bodies and alluvial deposits. Structural analysis identified the following deformation phases: Two ductile folding phases (F1 and F2) associated with the Pan-African Orogeny, with phase F1 dominating the axial trace oriented in the NE-SW direction (parallel to the Lurium Belt). F2 generated interference folds and circular/elliptical structures associated with post-F1 magmatic activity. A late brittle deformation phase (F3), characterized by three fault families (dominant NW-SE). These fractures served as conduits for the intrusion of gabbroic dikes (post-Pan-African basic magmatism). In conclusion, the work demonstrates the effectiveness of Remote Sensing for detailed mapping and validated the presence of shear zones (kinematic indicators), which represent crucial structural conduits for the occurrence and prospecting of associated mineral deposits (Skarn, Scheelita- Cassiterita e Fluorita-Helvita)