Seismic Interpretation and Analysis of the Messinian Salt System Offshore Lebanon

Abstract

We used 3D time seismic reflection data from the northern Levant basin offshore Lebanon to map the Messinian salt layer, understand its tectonic behavior, and recognize its effect on the formation of the offshore structures. To do so, we interpreted the seabed (i.e. seafloor), the top of salt (TOS), and the base of salt (BOS) horizons, and we generated their corresponding bathymetric and structural maps. In addition, we generated isochron maps in order to detect the variations in the lateral thicknesses of the sedimentary sections between (1) the seafloor and the TOS, and (2) the TOS and the BOS (i.e. the salt layer). The presented maps helped us understand the impact of the Messinian salt deformation on the geological structures both in the sub-salt and supra-salt sections. We also assessed the distribution and geometries of salt structures, and provided analysis of thick and thin salt deposits. We argue that the movement of the Messinian salt has led to the generation of elongated lows on the seafloor. In effect, the seafloor is dominated by grabens under which the Messinian salt forms reactive diapirs. Besides, we discuss the relationships between the overburden strata and salt bodies that include: (1) thickness and age relations, (2) contact relations, and (3) regional relations. Finally, we come up with new findings that enable geologists to have solid knowledge about the effect of the salt layer in terms of salt tectonics, and oil and gas companies to build on this knowledge and pursue further investigations on the potential hydrocarbon structures that are related to the Messinian salt deformation.