Identification of potential mineral exploration targets from the interpretation of aeromagnetic data covering the Sirwa region (Central Anti-Atlas, Morocco)

Abstract

Situated at the junction between the Moroccan High Atlas and the Anti-Atlas, the Sirwa Massif has always been a perfect target for mining exploration for its unique geological characteristics that provide an economically valuable concentrations of metals. It corresponds to a crustal uplift at an elevation above 2000 m that were slightly folded and lifted during the Hercynian and Alpine orogeny. The structural settings of this area are very complicated due to the acute shortage of surface and subsurface structural data. The aeromagnetic data represents a powerful tool for the identification and the delineation of the poorly exposed faults, that could promote the development of new ore deposits.The processing of the residual magnetic map was carried out to locate anomalies, define the trends and boundaries of the buried structures and identify the magnetic contacts that might represent faults, fractures or lithologic boundaries. This is done by the reduction to the north pole (RTP) filter and several edge detectors processes (i.e., total horizontal derivative, the tilt angle derivative and the 3D-Euler deconvolution). The orientations of lineaments extracted from the total horizontal derivative and Tilt derivative maps predominantly suggest NE-SW to ENE-WSW trending structures, in agreement with the post-Pan-African rifting event. However, we have identified a few NW-SE and NNW-SSE trending lineaments probably related to the recent Variscan movements. The 3D Euler deconvolution (ED) suggests a depth solution that ranges from 600 m to 3400 m. The deepest lineaments have an ENE-WSW direction, and the shallowest with a depth of about 600 m, shows a NE-SW/NW-SE direction. These results reveal new tectonic features that can be useful for future mine exploration