Levant Basin Research Articles

Hierarchy of source-to-sink systems — Example from the Nile distribution across the eastern Mediterranean

A standard source-to-sink approach examines sediment transport along an imaginary axis (regarded here as primary) extending between land, the continental margin and a nearby basin. This approach oversimplifies the development of depositional environments located off the axis (regarded here as secondary). Similarly, it imposes that factors affecting the primary source (e.g. climate) will directly be reflected in the secondary sink. The current study examines this suggested hierarchy in a confined basin, where the sedimentary budget remains closed. It evaluates the mechanism connecting between the primary and secondary axes. The study focuses on the Nile sedimentary system, across northeastern Africa and the eastern Mediterranean basin (primary axis) and the Levant depositional system (secondary sink). We hypothesize that since secondary river input into the Levant basin is negligible, the main secondary source is seafloor currents. The Levant Jet System (LJS) transported sediments from the Nile cone along the Levant margin at depths between 0 and 350m, during the Holocene and until today. Once the LJS reaches its capacity to transport sediments, the surplus falls downslope to the deep basin. By integrating seismic and bathymetric data, this paper suggests a unifying mechanism integrating deposition, erosion and transport of sediments across the Levant margin and basin throughout the Quaternary. Results show that during both highstand and lowstand conditions the primary source-to-sink axis delivers sediments to the deep basin via south to north meandering channels. The LJS transports sediments that build the shelf, while unconfined overspills slide downslope to accumulate across the continental rise. However, when sea levels drop, the capacity of the LJS weakens. This results in a drastic decrease in sedimentation across the shelf and rise, accompanied by confined downslope turbidity flows into the deep basin. We conclude that seafloor currents serve as an immediate supplier from the mouth of the primary source (i.e. a major river) to the off-axis system. Variations in seafloor current dynamics and their capacity to transport sediments will be directly reflected in the secondary sink. The primary continental source is expected to have only an indirect effect on the secondary sink.

First record of Red Sea goatfish Parupeneus forsskali (Osteichthyes: Mullidae) from the Syrian coast (Eastern Mediterranean)

This paper reports the first record of Red Sea goatfish Parupeneus forsskali (Fourmanoir and Gueze, 1976) from the Syrian coast. This record confirms the occurrence of the species in the Levant Basin. However, no sufficient data were carried out to date to support that a population is at present substantially established in the same area.

Erratum to: 3D thermal history and maturity modelling of the Levant Basin and its eastern margin, offshore–onshore Lebanon

Erratum to: 3D thermal history and maturity modelling of the Levant Basin and its eastern margin, offshore–onshore Lebanon

Foul play? On the rapid spread of the brown shrimp Penaeus aztecus Ives, 1891 (Crustacea, Decapoda, Penaeidae) in the Mediterranean, with new records from the Gulf of Lion and the southern Levant

Specimens of the penaeid shrimp Penaeus aztecus, a West Atlantic species, were collected off Le Grau du Roi, Gulf of Lion, France, and off the Israeli coast, Levant Basin, Mediterranean Sea. This alien species has been previously recorded off Turkey, Greece, Montenegro and the Tyrrhenian coast of Italy. The species identity was confirmed based on morphological characters and by sequencing 406 nucleotides of the 16S RNA gene and 607 nucleotides of the COI. The 16S rRNA sequences of the specimens collected in Israel, France and Italy were identical, and exhibited three different COI haplotypes. The near-concurrent records from distant locations in the Mediterranean put paid to the premise that P. aztecus was introduced into the Mediterranean Sea in ballast waters. A more prudent proposition is that many of these populations issue from illegal introductions. Potential risks to native biodiversity and economic value are the likely competition with commercially important native prawns, co-introduction of pathogens and parasites, and risk of infecting penaeid populations elsewhere in the Mediterranean Sea with Erythraean alien disease agents previously limited to the Levant.

3D thermal history and maturity modelling of the Levant Basin and its eastern margin, offshore–onshore Lebanon

In the last decade, the East Mediterranean Levant Basin has become a frontier hydrocarbon province. Several gas discoveries have been recorded in Miocene reservoirs offshore Israel, and seismic data suggest promising prospective plays in deeper intervals throughout the basin. Source rock quality, quantity, and distribution as well as thermal history are hitherto not well constrained, especially in the deep offshore. In this study, we present new source rock information from Jurassic to Paleocene intervals that prove the presence of several gas-prone and oil-prone potential source rocks along the eastern margin of the Levant Basin onshore Lebanon. None of the analysed onshore source rocks have reached sufficient thermal maturity for oil generation. However, 3D thermal history and maturity modelling indicate that these source rocks have reached thermal maturity in the offshore basin. Several potential petroleum systems have been suggested, including an Upper Cretaceous–Oligo-Miocene biogenic and thermogenic system in the deep basin, a Jurassic–Cretaceous system along the margin, and a Permian–Triassic system in the onshore. Sensitivity analysis in the poorly calibrated offshore basin showed a large uncertainty with respect to the depth of the oil and gas window and suggested an important effect of the depth of the lithospheric–asthenospheric boundary on the thermal history of the basin. The different scenarios tested in this study showed that the thickness of the biogenic zone below the Messinian salt would vary between 700 and 1500 m in the deep basin offshore Lebanon.

Growth of layer-bound normal faults under a regional anisotropic stress field

Abstract Layer-bound normal faults commonly form polygonal faults with fine-grained sediments early in their burial history. When subject to anisotropic stress conditions, these faults will be preferentially oriented. In this study we investigate how faults grow, evolve and interact within regional-scale layer-bound fault systems characterized by parallel faults. The intention is to understand the geometry and growth of faults by applying qualitative and quantitative fault analysis techniques to a 3D seismic reflection dataset from the Levant Basin, an area containing a unique layer-bound normal fault array. This analysis indicates that the faults were affected by mechanical stratigraphy, causing preferential nucleation sites of fault segments, which were later linked. Our interpretation suggests that growth of layer-bound faults at a basin scale generally follows the isolated model, accumulating length proportional to displacement and, when subject to an anisotropic regional stress field, resembling to a great extent classical tectonic normal faults.

Lithology and characteristics of the Messinian evaporite sequence of the deep Levant Basin, eastern Mediterranean

As the lithological composition of the Messinian salt sequence of the Levant Basin is still controversial and unconstrained, we reveal for the first time the lithology of the entire evaporite sequence from deep basin depth migrated seismic and borehole data. The data presented here shows that the seismic transparent layers are composed of pure and uniform halite while the reflective layers are bundles of thin clay layers interbedded in the halite background. The thin clay layers inside the deep basin evaporites have a cumulative thickness of 25–40m. High amplitude fan structures are observed on the deepest internal reflector which may suggest clay transportation. Among all the internal reflectors, the upper units are more deformed while the deeper units are more coherent and flat. Two sets of folds/faults are shown on the shallower intra-units: folds with NNE–SSW trending axes and thrust faults strike NW–SE. On a regional scale, the top salt reflector is generally horizontal while the other internal reflectors dip toward the NW. The shallowest intra-unit is the only one that has a wedge shape thickening to the NW, while the other intra-units generally have uniform thicknesses.

Coincidence or not? Interconnected gas/fluid migration and ocean–atmosphere oscillations in the Levant Basin

A growing number of studies on shallow marine gas/fluid systems from across the globe indicate their abundance throughout geological epochs. However, these episodic events have not been fully integrated into the fundamental concepts of continental margin development, which are thought to be dictated by three elements: tectonics, sedimentation and eustasy. The current study focuses on the passive sector of the Levant Basin on the eastern Mediterranean continental margin where these elements are well constrained, in order to isolate the contribution of gas/fluid systems. Single-channel, multichannel and 3D seismic reflection data are interpreted in terms of variance, chaos, envelope and sweetness attributes. Correlation with the Romi-1 borehole and sequence boundaries constrains interpretation of seismic stratigraphy. Results show a variety of fluid- or gas-related features such as seafloor and subsurface pockmarks, volumes of acoustic blanking, bright spots, conic pinnacle mounds, gas chimneys and high sweetness zones that represent possible secondary reservoirs. It is suggested that gas/fluid migrate upwards along lithological conduits such as falling-stage systems tracts and sequence boundaries during both highstands and lowstands. In all, 13 mid-late Pleistocene sequence boundaries are accompanied by independent evidence of 13 eustatic sea-level drops. Whether this connection is coincidental or not requires further research. These findings fill gaps between previously reported sporadic appearances throughout the Levant Basin and margin and throughout geological time from the Messinian until the present day, and create a unified framework for understanding the system as a whole. Repetitive appearance of these features suggests that their role in the morphodynamics of continental margins is more important than previously thought and thus may constitute one of the key elements of continental margin development.

New observations of alien foraminifera on the Turkish coasts of the Aegean Sea (2012-2015)

During the benthic foraminiferal surveys conducted on the Aegean coasts of Turkey between 2012-2015, new alien species have been observed. These were either recent introductions, such as Cornuspiroides striolatus (Brady), Nodobaculariella cristobalensis McCulloch, N. galapagosensis McCulloch, Pseudonodosaria discreta (Reuss), Polymorphina fistulosa (Cushman) or south to north range expansions of the species previously known to inhabit Levant Basin, Cyclorbiculina compressa (d’Orbigny). Besides, Amphistegina lobifera Larsen which has been known to inhabit Kuşadası Bay and nothwestern coasts of Karaburun Peninsula has also been abundantly observed around Doğanbey Bay. Warm submarine springs are suggested to be the main cause of these thermophilic species to settle and form stable populations on the Aegean cost of Turkey. On the other hand salinity variations may also help to the spreading of these aliens. Thus, it is suggested that new introductions may follow in the near future.

Origin of the Eastern Mediterranean: Neotethys rifting along a cryptic Cadomian suture with Afro-Arabia

The Eastern Mediterranean is a land-locked basin, a remnant of the Neotethys Ocean. It was formed in the Permian−Triassic as a result of the drift of the Tauride block from the Afro-Arabian margin of Gondwana. Herein, we show that rather than being a genuine Afro-Arabia crustal fragment, the Tauride block is underlain by late Neoproterozoic Cadomian basement, which differs significantly from the Neoproterozoic “Pan-African” basement of NE Africa from which it was detached. Resembling other Cadomian terranes of western Europe, the Tauride basement is chiefly a graywacke succession deposited in a mid- to late Ediacaran back-arc basin formed on the periphery of Afro-Arabia, above the southward-subducting proto-Tethys Ocean. The back-arc region was deformed and metamorphosed to various degrees and intruded by latest Ediacaran−Cambrian granites and volcanics during the Cadomian orogeny. Unlike the protracted (∼300 m.y.) Neoproterozoic crustal evolution recorded in Afro-Arabia, the Cadomian basement of the Taurides evolved briefly, over ∼50 m.y. We show that the entire cycle of sedimentation, metamorphism, and magmatism in the Tauride basement took place in the late Ediacaran−Cambrian and lagged after Neoproterozoic Pan-African orogeny and igneous activity in Afro-Arabia. The Cadomian orogeny accreted the Taurides, and adjoining peri-Gondwana Cadomian terranes, with an already-consolidated Afro-Arabian continent. Permian−Triassic rifting of the Eastern Mediterranean occurred close to the transition between these two domains. Rifting was thus inherited from, and superimposed on, late Ediacaran structures formed in front of the current Afro-Arabia margin of Gondwana during Cadomian orogeny. The boundary between the Cadomian edifice and the Pan-African crust of Afro-Arabia appears to lie presently on the southern margin of the Mediterranean, extending from Morocco in the west to Arabia in the east. Hence, the continental margin of the Eastern Mediterranean, including in the Levant Basin, is probably underlain by a thinned Cadomian crust.

First record of wedge sole, Dicologlossa cuneata (Actinopterygii: Pleuronectiformes: Soleidae), from the Levant Basin (eastern Mediterranean)

This paper reports the first record of a specimen of wedge sole, Dicologlossa cuneata (Moreau, 1881), from the Syrian coast, and also from the Levant Basin, constituting its easternmost extension range in the Mediterranean Sea. The specimen was examined, illustrated, measured, and weighed and the collected data are provided herein. This single capture of D. cuneata, however, cannot support a statement that a sustainable population of this fish has established itself in this area.

First record of Klein’s sole Synapturichthys kleinii (Osteichthyes: Soleidae) off the Syrian coast (eastern Mediterranean)

This paper reports the first record of Klein’s sole Synapturichthys kleinii (Risso, 1827) from the Syrian coast. This record confirms the occurrence of the species in the Levant Basin and its eastern extension range in the Mediterranean Sea. However, this single capture of S. kleinii cannot support that a sustainable population is at present substantially established in the same area.

Unique clay assemblages in the Levant basin (Haifa Bay) subsurface reflect a land–sea transition zone and restricted environments throughout the last ~ 1 m.y.

A subsurface sequence in Haifa Bay, the Levant basin, was studied for its clay mineralogy by X-ray diffraction (XRD) in order to examine the response of clay assemblages to sea-level changes and alternating environments over a long period, apparently longer than ever recorded before. The study was conducted on continuous cores of three boreholes that represent ~1m.y. of very shallow (<40m) and shallow (40–80m) water depths alternating with wetland and terrestrial sediments, including soils. Another aim of the current study was to evaluate the constancy of clay sources along this long record within a bay located at the northern end of the Nile cell. Marine samples, regardless of water depth, are characterized by low amounts of kaolinite+illite (<25%) and variable mix-layer illite-smectite (IS) compositions, in contrast to paleosols with high amounts of kaolinite+illite (30–60%) and illite-rich IS. The sandy permeable parent material of coastal paleosols enabled efficient leaching and major pedogenic clay transformations. Maximum soil development apparently occurred when glacial marine isotope stages were more humid (MIS 6 and MIS 26). When environmental changes were rapid previous clay assemblages were preserved, as indicated by wetland sediments that display pedogenic characteristics and coastal dunes that display marine characteristics. Closely-spaced boreholes yielded two unique marine clay provinces, not known before elsewhere in the Levant basin north of the Nile delta: 1. marine sediments from two boreholes on both sides of the Carmel fault are enriched by up to 90% palygorskite; 2. clean marine sand with a clay fraction dominated by discrete smectite or smectite-rich IS that occur within dark peloids, apparently fecal pellets. Two exotic minerals are occasionally present in trace amounts: clinoptilolite, derived from the nearby northeastern hinterland; and serpentine, derived from the remote Iskenderun Bay. Both unique clay provinces prevail throughout the sequence, indicating stable environmental conditions in south Haifa Bay for the last ~1m.y.

The enigma of the Jonah high in the middle of the Levant basin and its significance to the history of rifting

Recent giant gas discoveries within deeply buried structural highs in the middle of the Levant basin have attracted the attention of the industrial and academic communities striving to understand the origin of such structures, their relations to the tectonic history of the basin, and their evolution through time. Here we focus on the Jonah high, which is one of the largest structures in the basin and is particularly enigmatic in its geometry, dimensions and location compared to nearby structures. It is buried under more than 3km of Late Tertiary sediments, and is associated with one of the largest magnetic anomalies in the basin, though no significant gravity anomaly is observed. Previous studies raised several possibilities explaining its origin: an ancient horst related to the early stage of basin formation (Late Paleozoic or early Mesozoic); a Syrian Arc fold (Late Cretaceous to Neogene); a giant volcanic seamount; and an intrusive magmatic body.A reconstruction of the evolution of this structure is proposed here based on newly produced pre-stack depth migration of five selected seismic reflection lines crossing the Jonah high combined with a basin-wide interpretation of more than 500 2-D time-migrated lines. We suggest that the Jonah high is a horst bounded by grabens, most probably formed during continental breakup related to the Neo-Tethys formation. However, unlike other extensional structures that were reactivated and inverted during the Syrian Arc deformation, the Jonah high was never reactivated. Rather, it formed a prominent seamount that persisted for 120–140Ma until the Early Miocene, when it was finally buried. In a wider perspective the Jonah horst is similar to the Eratosthenes seamount, a fragment of continental crust between the Levant and Herodotus basins.

The characteristics of carbonate system recovery during a relatively dry event in a mixed carbonate/siliciclastic environment in the Pelsonian (Middle Triassic) proximal marginal marine basins: A case study from the tropical Tethyan northwest Gondwana margins

Eight early-mid Pelsonian (Middle Triassic) marine sedimentary successions, an outcrop and subsurface sections of the Ra'af Formation from the northwest Gondwana margins facing the southeast corner of the tropical western Tethyan seaway assigned to the southern Intertropical Convergence Zone (ITCZ) (south Israel, Levant Basin, north Arabian plate) are the focus of this work. The successions, especially with the exclusive outcrop at Har 'Arief, are a golden opportunity to observe the still connected transitional zone between the huge siliciclastic domains derived from Gondwana hinterland parts (north Arabian plate) and the open, tropical Tethyan marine carbonate domain and their mutual relationships.This multidiscipline research tracks a carbonate recovery attempt in a dominant siliciclastic system. The recovery effort was characterized by starved sedimentary conditions, basin-constrained oxygen-stressed environments, and low-diverse, autochthonous burrowed sediments barren of other faunal remains. Low-diverse fossiliferous allochthonous beds, transported from higher sites on the slopes, revealed differential distributions of echinoids, mollusks and especially foraminifera (large Pilammina-Pilamminella versus small glomospirids); these variances were attributed to different environmental conditions on the slopes of each basin-type and illuminate some constraints on their distribution pattern and climate affinity in the Triassic, southern ITCZ mixed carbonate/siliciclastic, sedimentary system. The carbonate recovery phase is ascribed to a relatively dry period in the hinterland rather than to sea-level rise; this dry period, which interrupted the relatively humid climate in the northern tropical Gondwana during the Pelsonian, is represented by the constant, although with some perturbations, siliciclastic sedimentary system that prevailed in the southeastern corner of the Tethys seaway during the Anisian. Insights from the symmetric and asymmetric correlation of climate fluctuations in the hinterlands of the southeastern European basins (northern hemisphere) and this work (from the southern hemisphere), both embracing basins ascribed to the western tropical Tethyan seaway, illuminate the possible effects of the ICTZ behavior pattern and possible extra-tropical forces on the climate variations.

Levant jet system—effect of post LGM seafloor currents on Nile sediment transport in the eastern Mediterranean

Sedimentary development of a continental margin is directly related to seafloor current dynamics. Yet the linkage between the processes remains vague due to the different time scales they represent. To narrow this gap we focus on the thoroughly studied distribution system of Nile derived sediments across the Levant continental margin (eastern Mediterranean). These sediments dominate the Late Quaternary stratigraphy of the entire margin. Their mobilization has been explained exclusively by longshore transport, while oceanographic evidence from the basin and margin are not incorporated in the known mechanism. New data indicates that longshore mechanism is part of a much larger system. Based on integrated interpretation of multibeam bathymetry, high-resolution single-channel seismic reflection and oceanographic (temperature, salinity and chlorophyll) data we suggest a jet current system mobilizes the Levant Surface Water (LSW), Levant Intermediate Water (LIW) and Atlantic Water (AW) northwards along the margin, between 0 and 400m water depths. On the seafloor, contourite currents form elongated along-strike morphologies. Below 400m along-dip gravity flows dominate sediment transport to down the slope, below the Eastern Mediterranean Deep Water (EMDW). Initiation of this mechanism during the Pleistocene–Holocene transition and not at the end of the Last Glacial Maximum (LGM) indicates a gradual recovery of the thermo-haline circulation. Current intensification in the early Holocene may have also increased water stratification. This comprehensive mechanism explains sediment transport along the entire depth range of the continental margin, while integrating seafloor currents, morphology, as well as their relation to sea level rise and stratigraphy of water masses in the Levant basin since the LGM. Given the consistency of seafloor currents throughout the Holocene we propose to address them as the Levant Jet System.

Multi‐scale constraints of sediment source to sink systems in frontier basins: a forward stratigraphic modelling case study of the Levant region

AbstractRecent scientific work has highlighted the presence of an up to 12 km thick Cenozoic siliclastic and carbonate infill in the Levant Basin. Since the Late Eocene, several regional geodynamic events affecting Afro‐Arabia and Eurasia (collision and strike slip deformation) induced marginal uplifts. The initiation of local and long‐lived regional drainage systems in the Oligo‐Miocene period (e.g., Lebanon, Arabia and Nile) provoked a change in the depositional pattern along the Levant region from carbonate‐dominated to mixed clastic‐rich systems. Herein, we explore the importance of multi‐scale constraints (i.e., seismic, well and field data) in the quantification of subsidence history, sediment transport and deposition of a Middle to Upper Miocene “multi‐source” to sink system along the northern Levant frontier region. Through a comprehensive 4D forward stratigraphic modelling workflow, we suggest that the contribution to basin infill is split between proximal and more distal clastic sources as well asin situcarbonate and hemipelagic deposition. The results show that single‐source scenarios could not reasonably satisfy the basin‐scale constraints. The worldwide application of such new multi‐disciplinary workflows in frontier regions highlights the additional data constraints that are needed to de‐risk highly uncertain geological models in the hydrocarbon exploration phase.

A checklist of the deep sea fishes of the Levant Sea, Mediterranean Sea.

We list sixty five fish species collected at depths greater than 500 m in the Levant Basin, including 10 depth records. The Levantine bathyal ichthyofauna is characterized by its eurybathy, with an upper bathymetric boundary that permitted penetration of the shallow Gibraltar and Siculo-Tunisian sills, and a much lower bathymetric boundary than recorded for conspecifics elsewhere. The opportunistic and resilient ichthyofauna re-colonized recently the deep-sea following the last anoxic event (~ 6 kyr), forming assemblages notably distinct from those in the western Mediterranean. The exploration and production of deep seabed hydrocarbons have raised the specter of severe direct impacts to the deep habitats. There is an urgent need for documenting the full extent of deep-sea biodiversity, and for providing information for the development of competent and pragmatic management plans and effective conservation policies.

Energy Security and the Cyprus Question

In February 2014, Nikos Anastasiades, the President of the Republic of Cyprus and Dervis Eroglu, the Turkish-Cypriot leader, signed a Joint Declaration that established certain “ground-rules” upon which the then stalled peace talks -aiming at the island’s reunification- could be revived. The main stimulant prompting this evolution was the discovery of new energy sources in the Eastern Mediterranean, and especially offshore the RoC. In October 2014, Turkish navigational warning notified mariners that Turkey would soon perform its seismic surveys in sea areas that encroach on Cyprus’s EEZ, raising concerns on the escalation of the intractable and protracted Cyprus conflict. Aim of this research project is to provide readers with an insight on how the flow between energy and power politics is played out in the Eastern Mediterranean. Suggesting that the existing tensions extend beyond the struggle over the existing material energy assets in the seabed of the Levant Basin, the project casts light upon the notion of energy security by setting forth the indicators it is composed of. While scrutinizing the statements of the leaders on these events and seeking to highlight the security discourses they are coming up with, the project resorts to discourse analysis.

The impact of salt on the late Messinian to recent tectonostratigraphic evolution of the Cyprus subduction zone

AbstractMessinian evaporites of locally more than 3‐km thickness occupy the subduction zone between Cyprus and Eratosthenes Seamount. Based on a dense grid of seismic reflection profiles, we report on compressional salt tectonics and its impact on the Late Miocene to Quaternary structural evolution of the Cyprus subduction zone. Results show that evaporites have experienced significant post‐Messinian shortening along the plate boundary. Shortening has initiated allochthonous salt advance between Cyprus and Eratosthenes Seamount, representing an excellent example of salt which efficiently escapes subduction and accretion. Further east, between Eratosthenes Seamount and the Hecataeus Rise, evaporites were compressionally inflated without having advanced across post‐Messinian strata. Such differences in the magnitude of salt tectonic shortening may reflect a predominately north–south oriented post‐Messinian convergence direction, raising the possibility of a later coupling between the motion of Cyprus and Anatolia than previously thought. Along the area bordered by Cyprus and Eratosthenes Seamount a prominent step in the seafloor represents the northern boundary of a controversially debated semi‐circular depression. Coinciding with the southern edge of the salt sheet, this bathymetric feature is suggested to have formed as a consequence of compressional salt inflation and seamount‐directed salt advance. Topographic lows on top of highly deformed evaporites are locally filled by up to 700 m of late Messinian sediments. The uppermost 200 m of these sediments were drilled in the course of ODP Leg 160 and interpreted to represent Lago Mare‐type deposits (Robertson, Tectonophysics, 1998d, 298, 63‐82). Lago Mare deposits are spatially restricted to the western part of the subduction zone, pinching out towards the east whereas presumably continuing into the Herodotus Basin further west. We suggest a sea level control on late Messinian Lago Mare sedimentation, facilitating sediment delivery into basinal areas whereas inhibiting Lago Mare deposition into the desiccated Levant Basin. Locally, early salt deformation is believed to have provided additional accommodation space for Lago Mare sedimentation, resulting in the presently observed minibasin‐like geometry.