Mineral deposits of northeastern Algeria (southern Medjerda mounts and diapiric zone) : regional-scale structural controls, spatial distribution, and importance of geophysical lineaments

Abstract

The Southern of Medjerda mounts and the diapiric zone in the northeast of Algeria host a significant hydrothermal Pb-Zn-Fe-Ba (±Cu, ±F, ±Sr, ±Au, ±Ag) ore deposits and showings. The integration of geophysical data (ground gravity and aeromagnetic datasets) was undertaken in order to clarify and define the litho-structural control of the mineralization. These geophysical surveys allowed the identification of several prominent geophysical features. Some of these features correspond to lithological contacts; others reflect tectonic trough zones, Triassic salt diapirs, sedimentary basins, anticlines, and faults. The preferential (primary) trend of structural features within the study area is NE–SW and NW–SE. Integrated interpretation of geological and regional geophysical data helped the identification of the main factors controlling the distribution of mineral deposits within the study area. Most of the mineral deposits are likely to be found along or near major NE–SW/NW–SE deep lineaments. These major deeper lineaments have probably controlled the kinematic evolution of geological structures, sedimentary basins, and the ascension of the Triassic rocks during the lower Cretaceous. They seem to play a significant role providing favorable pathways for the migration and ascent of mineralized fluids to depositional sites along smaller faults into the sedimentary cover or at contact between Triassic salt outcrops and lower Cretaceous carbonate rocks