Seismic, gravity, and wire line logging characterization of the Zéramdine fault corridor and its influence in the deep Miocene aquifers distribution (east-central Tunisia)

Abstract

In the Jemmel–Zeramdine region, the combined analysis of petroleum well data, seismic reflection profiles, and gravity data show the presence of the Zeramdine fault corridor, which was activated in the Neogene period. Both tectonic activity and fluvio-deltaic sedimentation are the origin of the lithologic and hydrodynamic heterogeneities. Thus, the Zeramdine fault corridor constitutes a limit between two hydraulic systems formed by Miocene sandy reservoir layers. These reservoirs have not been exploited yet and could be new water resources which can extremely benefit the region; only the upper one is exploited in the Jemmel–Bembla and Zeramdine–Beni Hassen deep aquifers. The wire line logging, seismic reflection, and gravity interpretations show the distribution of the Miocene layers which formed the Sahel Miocene deep aquifers. The Zeramdine fault corridor leads to a spatial variability in number, distribution, depths, and thicknesses of these reservoir layers. In the northern part of the Zeramdine fault corridor, seven layers were highlighted; their thicknesses range between 15 and 105 m. However, in the southern part, only four strata were deposited: their thicknesses vary between 45 and 53 m. The total porosity of the studied aquifers is about 30%.