Remote sensing applied to investigate the emplacement of the Seis Lagos Carbonatitic Complex and the lateritic Nb-deposit associated (Amazonas State, Brazil)

Abstract

The main goals of this study were to identify geological structures that controlled the emplacement of the Seis Lagos Carbonatite Complex and contribute to the knowledge of the associated deposit, through the delimitation of the lateritic crust, the identification of internal structures and hydrothermal zones, where higher concentrations of Nb and REE may occur. Geophysical techniques, analysis of digital terrain elevation and processing techniques of orbital data were employed. The main regional structure has E-W direction and length of about 400 km. The positioning of the SLCC occurred where it is intersected by structures trending NE-SW and NW-SE. The boundaries of the lateritic crust are largely rectilinear, suggesting brittle structures, that may be the walls of the magma conduct, following open faults and fractures, or faults that affect the body after its crystallization. The main structures affecting the deposit have EW or NNW-SSE direction, controlled the formation of valleys and ridges, and karst processes with basin formation; therefore exerted role during laterization. Clayey zones likely related to hydrothermal processes were identified in four structures.