Integrated geophysical approach for ore exploration: Case study of Sidi Bou Aouane–Khadhkhadha Pb–Zn province – Northern Tunisia

Abstract

AbstractWe carried out an integrated interpretation of available geophysical data (gravity and electrical data) in Sidi Bou Aouane–Khadhkhadha Pb–Zn province, located in a Neogene basin south of the Alpine thrust‐belt front in northern Tunisia. The interpretive approach of gravity data was done based on the Fourier transformation and spectral analysis to extract the residual component. Furthermore, edge enhancement techniques (tilt angle, total horizontal derivative) were applied to image the underlying lineaments in the study area. The computed gravity maps reveal multiple NE–SW hidden faults considered potential mineralization targets, referring to geological information. Detrital formations, known as containers of disseminated Pb–Zn mineralization, are expressed by low gravity responses. Resistivity and chargeability 3D inversion was conducted concurrently through on an iterative approach based on the conventional least‐squares algorithm and “incomplete Gauss‐Newton” as an optimization method. The initial model was defined based on drill‐hole data and geological knowledge. Inverted resistivity confirms the basin architecture expressed by gravity data. The combined interpretation of inverted resistivity and chargeability correlated to borehole and outcrops allows the definition of different electrical ranges associated to different lithologies and mineralization type and contents. A new potential target, expressing the same electrical signature of mineralization, is evidenced northward Khadhkhadha old mine. In addition, a potential copper concentration area was proven based on its electrical responses south Sidi Bou Aouane mine. 2.5D gravity modelling supports the evidenced interpreted target. The revealed results provided evidence for future interpretations of further geological structures, along with evaluations of mineral resources.