Multiphase Structural Evolution and Geodynamic Implications of Messinian Salt‐Related Structures, Levant Basin, Offshore Israel

Abstract

Speculations surround salt deformation in the Mediterranean Basins, both related to the deformation history and the triggers for halokinesis since the onset of the Messinian Salinity Crisis. This work presents a detailed description of the mechanisms driving internal and external deformation of a salt giant from the Levant Basin, offshore Israel. The intrasalt siliciclastic layers generate good internal reflectivity within the Messinian evaporites, allowing a thorough elucidation of the complex evolution and nature of syn-Messinian and post-Messinian structures. We have identified three distinct phases of deformation in the deep basin, based on the orientation, timing, and geometry of their related structures: The first phase is characterized by small-scaled, gravity-driven, contractional faults and folds oriented N-S that have been overprinted by a second syn-Messinian, NW-SE trending, deformation phase affecting the clastic bundles. This latter deformation phase is the cause of truncation of the intrasalt stringers on the intra-Messinian truncation surface. The third deformation phase occurred in the Pleistocene and affected all strata from the Messinian salt to the seabed. This deformational phase produced thrust, strike-slip, and normal faults, but the dominant orientation of the thrust faults and folds is NNW-SSE. Our study demonstrates that the first deformation phase was caused by regional uplift along the Levant margin during the Messinian, the second is a response to basin subsidence toward the Cyprus Arc, also syn-Messinian, and the third phase is likely related to the reorganization of the African-Eurasian plate boundary and activity along the Dead Sea Transform after the Messinian Salinity Crisis.Plain Language Summary A thick body of alternating evaporites and claystones was deposited in the Mediterranean Sea during the infamous Messinian Salinity Crisis, between 5.93 and 5.33 million years ago. This event is in itself poorly understood, as both the cause(s) and the consequence(s) of this crisis is heavily disputed. In this study, we use traditional seismic interpretation as well as geometrical observations and seismic attribute analysis to understand the tectonic movements and how they have generated different fault types in the subsurface of offshore Israel during and after the deposition of the evaporite package. We present three different deformation phases and discuss their possible trigger mechanisms. The good quality of the seismic data used in the study has provided us with excellent examples of thrust, strike-slip, and normal faults in the area. These classical examples offer a clearer picture of the tectonic history of the study area, which has wider application in understanding tectonic histories of many basins worldwide.

Evidence of sea level drawdown at the end of the Messinian salinity crisis and seismic investigation of the Nahr Menashe unit in the northern Levant Basin, offshore Lebanon

“…The arc system has been reactivated multiple times since then, most recently during an intense deformation phase in the Early Miocene (Gardosh & Druckman, ; Walley, ). Since the Late Miocene, much of the contractional movement in the basin has migrated to the onshore Dead Sea Transform (DST), and compressional structures in the post‐Miocene strata are believed to be a product of movement along the DST and radial gravity spreading of the Nile Cone (Kartveit et al, ). Margin uplift associated with the DST resulted in erosion and formation of deeply incised canyons along the Levant Margin which, supplemented by sediment supply from North African river systems, led to the deposition of carbonate–siliciclastic sediments in the deep basin during several phases extending into the Late Miocene (Druckman, Buchbinder, Martinotti, Tov, & Aharon, ; Gardosh, Druckman, Buchbinder, & Calvo, ; Papadimitriou et al, ).…”

“…In this study, we have adopted the seismic stratigraphic framework and nomenclature of Feng et al () and Gvirtzman et al () where the six Messinian seismic units, between the bottom surface/Base Salt (BS) and the IMTS, are named (from deep to shallow): ME1, ME2, MC1, ME3, MC2 and ME4 (Figure ). These units have been subject to substantial deformation both during and after the MSC, demonstrated by truncation and deformation of the IMTS (Kartveit et al, ).…”

“…The arc system has been reactivated multiple times since then, most recently during an intense deformation phase in the Early Miocene (Gardosh & Druckman, 2006;Walley, 1998). Since the Late Miocene, much of the contractional movement in the basin has migrated to the onshore Dead Sea Transform (DST), and compressional structures in the post-Miocene strata are believed to be a product of movement along the DST and radial gravity spreading of the Nile Cone (Kartveit et al, 2018). Margin uplift associated with the | 829 EAGE KARTVEIT ET Al.…”

“…The Plio-Quaternary succession consists of up to a kilometer of fine-grained material in the deep basin, while sandy and silty sediments along the Levant Margin accumulates to more than 1.5 km and currently prograding basinwards (Gardosh et al, 2008;Hübscher, Betzler, & Reiche, 2016;Lazar, Lang, & Schattner, 2016). The Messinian to Recent succession in the Levant Basin has undergone drastic deformation in several deformation phases (Bertoni & Cartwright, 2007;Gvirtzman et al, 2013;Kartveit et al, 2018;Netzeband et al, 2006). Generally the deformation in the Levant basin has been related to three different stress domains stretching semi-parallel to the basin margin (Cartwright & Jackson, 2008;Solem, 2014), but the intra-Messinian stringers also display distinct individual deformation patterns (Kartveit et al, 2018).…”

“…The Messinian to Recent succession in the Levant Basin has undergone drastic deformation in several deformation phases (Bertoni & Cartwright, 2007;Gvirtzman et al, 2013;Kartveit et al, 2018;Netzeband et al, 2006). Generally the deformation in the Levant basin has been related to three different stress domains stretching semi-parallel to the basin margin (Cartwright & Jackson, 2008;Solem, 2014), but the intra-Messinian stringers also display distinct individual deformation patterns (Kartveit et al, 2018).…”