scholarly journals Seismic Characterization and Depositional Significance of the Nahr Menashe deposits: Implications for the terminal phases of the Messinian Salinity Crisis in the Northeast Levant Basin, Offshore Lebanon.

2021 ◽  
Author(s):  
SM Mainul Kabir ◽  
DaVID Iacopini ◽  
Adrian Hartley ◽  
Vittorio Maselli ◽  
Davide Oppo
Keyword(s):  
Messinian Salinity Crisis ◽  
Seismic Characterization ◽  
Levant Basin

Intense salt deformation in the Levant Basin in the middle of the Messinian Salinity Crisis

2013 ◽  
Vol 379 ◽  
pp. 108-119 ◽  
Author(s):  
Zohar Gvirtzman ◽  
Moshe Reshef ◽  
Orna Buch-Leviatan ◽  
Zvi Ben-Avraham
Keyword(s):  
Messinian Salinity Crisis ◽  
Levant Basin

Drainage systems and their relations to the Messinian Salinity Crisis in the Levant Basin

2020 ◽  
Author(s):  
Jimmy Moneron ◽  
Zohar Gvirtzman
Keyword(s):  
Salt Tectonics ◽  
Messinian Salinity Crisis ◽  
Time Intervals ◽  
Drainage Systems ◽  
Resolution Imaging ◽  
Levant Basin ◽  
Channel Patterns ◽  
Seismic Reflection Profiles ◽  
Short Time ◽  
Channel Systems

<p>New high-resolution imaging of recently acquired data in the Levant basin shed light on very dense channel systems. The processes behind their origin, timing and direction - during the different stages of the Messinian Salinity Crisis (MSC) - is still unresolved and partly understood. Discoveries of such drainage systems raise questions on a past topography and mechanisms responsible for the channel morphologies, the understanding of these channel patterns is thus essential for a meaningful assessment of such mechanisms involved in the context of the MSC and its aftermath. Our results show that the drainage direction was undergoing extreme changes during short time intervals in the Levant Basin. Indeed, new maps presented here indicate different past drainage orientations, which is in contrast to the current-day turbidite channels - draining the Sinai-Levant continental margin northward towards the Cyprus Arc. We hypothesize from these results that drainage change, from southwest to north, expresses northward tilting of the basin towards the Cyprus subduction zone, however, when exactly did this tilting occur? Deciphering the timing of such events is important in order to get a better understanding of tectonostratigraphic settings, controlling depocenter locations in the Levant basin in the MSC. We also suggest that the unique pattern of channels over the Intra-Messinian Truncation Surface (IMTS), expresses a complex seafloor relief which was mainly controlled by salt tectonics induced thrusts faults.</p><p>Keywords: Messinian Salinity Crisis, Channel systems, Evaporites, Seismic Reflection Profiles</p>

scholarly journals Leaky salt: pipe trails record the history of cross-evaporite fluid escape in the northern Levant Basin, Eastern Mediterranean

2021 ◽  
Author(s):  
Davide Oppo ◽  
Sian Evans ◽  
Christopher A-L Jackson ◽  
David Iacopini ◽  
SM Mainul Kabir ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Tectonic Evolution ◽  
Eastern Mediterranean ◽  
Early Pleistocene ◽  
Salt Tectonics ◽  
Messinian Salinity Crisis ◽  
Seal Failure ◽  
History Of ◽  
Levant Basin

<p>Hydrocarbon escape systems can be regionally active on multi-million-year timescales. However, reconstructing the timing and evolution of repeated escape events can be challenging because their expression may overlap in time and space. In the northern Levant Basin, eastern Mediterranean, distinct fluid escape episodes from common leakage points formed discrete, cross-evaporite fluid escape pipes, which are preserved in the stratigraphic record due to the coeval Messinian salt tectonics.</p><p>The pipes consistently originate at the crest of prominent sub-salt anticlines, where thinning and hydrofracturing of overlying salt permitted focused fluid flow. Sequential pipes are arranged in several kilometers-long trails that were progressively deformed due to basinward gravity-gliding of salt and its overburden. The correlation of the oldest pipes within 12 trails suggests that margin-wide fluid escape started in the Late Pliocene/Early Pleistocene, coincident with a major phase of uplift of the Levant margin. We interpret that the consequent transfer of overpressure from the deeper basin areas triggered seal failure and cross-evaporite fluid flow. We infer that other triggers, mainly associated with the Messinian Salinity Crisis and compressive tectonics, played a secondary role in the northern Levant Basin. Further phases of fluid escape are unique to each anticline and, despite a common initial cause, long-term fluid escape proceeded independently according to structure-specific characteristics, such as the local dynamics of fluid migration and anticline geometry.</p><p>Whereas cross-evaporite fluid escape in the southern Levant Basin is mainly attributed to the Messinian Salinity Crisis and compaction disequilibrium, we argue that these mechanisms do not apply to the northern Levant Basin; here, fluid escape was mainly driven by the tectonic evolution of the margin. Within this context, our study shows that the causes of cross-evaporite fluid escape can vary over time, act in synergy, and have different impacts in different areas of large salt basins.</p>

Levant Basin as a key for Understanding the Messinian Salinity Crisis: Challenging the Desiccation Paradigm

2020 ◽  
Author(s):  
Zohar Gvirtzman ◽  
Vinicio Manzi ◽  
Ran Calvo ◽  
Ittai Gavrieli ◽  
Rocco Gennari ◽  
...  
Keyword(s):  
High Resolution ◽  
Mediterranean Sea ◽  
Water Column ◽  
Mediterranean Basin ◽  
Eastern Mediterranean ◽  
Messinian Salinity Crisis ◽  
Seismic Surveys ◽  
Salt Rocks ◽  
The Mediterranean ◽  
Levant Basin

<p>The Messinian salinity crisis (MSC) is an extreme event in Earth history during which a salt giant (>1×10<sup>6</sup> km<sup>3</sup>) accumulated on the Mediterranean seafloor within ~640 kyrs. The Messinian salt giant was formed about 6 million years ago when the restriction of water exchanges between the Atlantic Ocean and the Mediterranean Sea turned the Mediterranean into an enormous saline basin. After more than 40 years of research, the timing and the depositional environments of shallow (<200 m) and intermediate (200-1000 m) water-depth Messinian basins are known quite well from onshore outcrops. But what happened in the deepest portions of the Mediterranean Sea is still unclear, because the information about offshore successions is mainly based on geophysical data with no rock samples that can be dated.</p> <p>The Levant Basin is the only deep Mediterranean basin where the entire Messinian section has been penetrated by wells tied to high resolution 3D seismic surveys. Here we present two studies challenging the desiccation paradigm dominating the MSC scientific literature for more than 40 years.</p> <p>The first study focuses on the nearly flat top erosion surface (TES) that truncates a basinward-tilted Messinian evaporitic succession. This truncation is commonly interpreted to be the result of subaerial erosion at the end of the MSC. However, based on high resolution seismic surveys and wireline logs, we show that (1) the TES is actually an intra-Messinian truncation surface (IMTS) located ~100 m below the Messinian-Zanclean boundary; (2) the topmost, post-truncation, Messinian unit is very different from the underlying salt deposits and consists mostly of shale, sand, and anhydrite showing typical <sup>87</sup>Sr/<sup>86</sup>Sr values and fauna assemblages from stage 3; and (3) the flat IMTS is a dissolution surface related to significant dilution and stratification of the water column during the transition from stage 2 to stage 3. We suggest that dissolution occurred upslope where salt rocks at the seabed were exposed to the upper diluted brine, while downslope the salt rocks were preserved because submerged in the deeper halite-saturated layer. The model, which requires a stratified water column, is inconsistent with a complete desiccation of the eastern Mediterranean Sea.</p> <p>The second study focuses on the onset of the Messinian salinity crisis in the deep Eastern Mediterranean basin. Biostratigraphy and astronomical tuning of the Messinian pre-salt succession in the Levant Basin allows for the first time the reconstruction of a detailed chronology of the MSC events in deep setting and their correlation with marginal records that supports the CIESM (2008) 3-stage model. Our main conclusions are (1) MSC events were synchronous across marginal and deep basins, (2) MSC onset in deep basins occurred at 5.97 Ma, (3) only foraminifera-barren, evaporite-free shales accumulated in deep settings between 5.97 and 5.60 Ma, (4) deep evaporites (sulfate and halite) deposition started later, at 5.60 Ma. The wide synchrony of events implies inter-sub-basin connection during the whole salinity crisis and is not compatible with large sea-level fall that would have separated the eastern and western basins producing diachronic processes.</p>

Evidence of Clastic Evaporites In the Canyons of the Levant Basin (Israel): Implications For the Messinian Salinity Crisis

2013 ◽  
Vol 83 (11) ◽  
pp. 942-954 ◽  
Author(s):  
S. Lugli ◽  
R. Gennari ◽  
Z. Gvirtzman ◽  
V. Manzi ◽  
M. Roveri ◽  
...  
Keyword(s):  
Messinian Salinity Crisis ◽  
Levant Basin

scholarly journals Seismic markers of the Messinian salinity crisis in the deep Ionian Basin

2020 ◽  
Author(s):  
Angelo Camerlenghi ◽  
Anna Del Ben ◽  
Christian Hübscher ◽  
Edy Forlin ◽  
Riccardo Geletti ◽  
...  
Keyword(s):  
Sedimentary Basins ◽  
Western Mediterranean ◽  
Depositional Environments ◽  
Ecological Crisis ◽  
Messinian Salinity Crisis ◽  
Deep Basin ◽  
Northern Adriatic ◽  
Messinian Evaporites ◽  
Stratal Architecture ◽  
Levant Basin

<p>We conduct the seismic signal analysis on vintage and recently collected multichannel seismic reflection profiles from the Ionian Basin to characterize the deep basin Messinian evaporites. These evaporites were deposited in deep and marginal Mediterranean sedimentary basins as a consequence of the “salinity crisis” between 5.97 and 5.33 Ma, a basin‐wide oceanographic and ecological crisis whose origin remains poorly understood. The seismic markers of the Messinian evaporites in the deep Mediterranean basins can be divided in two end‐members, one of which is the typical “trilogy” of gypsum and clastics (Lower Unit – LU), halite (Mobile Unit – MU) and upper anhydrite and marl layers (Upper Unit – UU) traced in the Western Mediterranean Basins. The other end‐member is a single MU unit subdivided in seven sub‐units by clastic interlayers located in the Levant Basin. The causes of these different seismic expressions of the Messinian salinity crisis (MSC) appear to be related to a morphological separation between the two basins by the structural regional sill of the Sicily Channel. With the aid of velocity analyses and seismic imaging via prestack migration in time and depth domains, we define for the first time the seismic signature of the Messinian evaporites in the deep Ionian Basin, which differs from the known end‐members. In addition, we identify different evaporitic depositional settings suggesting a laterally discontinuous deposition. With the information gathered we quantify the volume of evaporitic deposits in the deep Ionian Basin as 500,000 km3 Å} 10%. This figure allows us to speculate that the total volume of salts in the Mediterranean basin is larger than commonly assumed. Different depositional units in the Ionian Basin suggest that during the MSC it was separated from the Western Mediterranean by physical thresholds, from the Po Plain/Northern Adriatic Basin, and the Levant Basin, likely reflecting different hydrological and climatic conditions. Finally, the evidence of erosional surfaces and V‐shaped valleys at the top of the MSC unit, together with sharp evaporites pinch out on evaporite‐free pre‐ Messinian structural highs, suggest an extreme Messinian Stage 3 base level draw down in the Ionian Basin. Such evidence should be carefully evaluated in the light of Messinian and post‐Messinian vertical crustal movements in the area. The results of this study demonstrates the importance of extracting from seismic data the Messinian paleotopography, the paleomorphology and the detailed stratal architecture in the in order to advance in the understanding of the deep basins Messinian depositional environments.</p>

The role of the Nahr Menashe in the Messinian Salinity Crisis: formation, dissolution and fluvial incision of the top evaporite unit in the NE Levant Basin, Eastern Mediterranean

2021 ◽  
Author(s):  
SM Mainul Kabir ◽  
David Iacopini ◽  
Adrian Hartley ◽  
Vittorio Maselli ◽  
Davide Oppo
Keyword(s):  
Eastern Mediterranean ◽  
Messinian Salinity Crisis ◽  
3D Seismic ◽  
Fluvial Erosion ◽  
Base Level ◽  
Fluvial Incision ◽  
Formation And Evolution ◽  
New Interpretation ◽  
Levant Basin

<p>The Nahr Menashe Unit (NMU), which forms the uppermost part of the Messinian succession,  is one of the most cryptic and elusive sedimentary units present in the Levant basin (Eastern Mediterranean). We use a high-resolution 3D seismic dataset from offshore Lebanon to propose a new interpretation for its formation and evolution. The NMU varies laterally across the basin both in thickness and internal seismic characteristics. The variably coherent cyclic seismic packages affected by fracturing, faulting suggests that the NMU represent a reworked, layered evaporite succession interbedded with siliciclastics derived from both the Lebanon Highlands and the Latakia Ridge. Widespread semi-circular depressions, random linear imprints, passive surface collapsing and residual mound features within the NMU suggest that post depositional diagenetic and/or strong dissolution process often affected its evaporite-rich subunits. The well-known extended valley and tributary channel systems characterising the uppermost NMU shows mainly erosional rather than depositional features. Erosion started after deposition of NMU as a consequence of the maximum base level fall during the last phase of the Messinian Salinity Crisis (MSC). The channel and valley system were subsequently infilled by layered sediments here interpreted to represent post-MSC deep water marine reflooding. In conclusion, our analyses suggest the NMU can be interpreted as a mixed evaporite-siliciclastic system deposited in a shallow marine or marginal environment, which subsequently experienced fluvial erosion and later burial by transgressive/high-stand sediments.</p>

Sign in / Sign up

Export Citation Format

Share Document