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Wout Krijgsman - One of the best experts on this subject based on the ideXlab platform.

  • palaeogeographic evolution of the late miocene rifian corridor morocco reconstructions from surface and subsurface data
    Earth-Science Reviews, 2018
    Co-Authors: Walter Capella, Frederik J Hilgen, Francisco Javier Sierro, N Barhoun, Rachel Flecker, T J Kouwenhoven, Liviu Matenco, M A Tulbure, M Z Yousfi, Wout Krijgsman
    Abstract:

    Abstract The Rifian Corridor was one of the Mediterranean–Atlantic seaways that progressively restricted and caused the Messinian Salinity Crisis (MSC). Many key questions concerning the controls on the onset, progression and termination of the MSC remain unanswered mainly because the evolution of these seaways is poorly constrained. Uncertainties about the age of restriction and closure of the Rifian Corridor hamper full understanding of the hydrological exchange through the MSC gateways: required connections to sustain transport of salt into the Mediterranean for the primary-lower gypsum and halite stages. Here we present integrated surface-subsurface palaeogeographic reconstructions of the Rifian Corridor with improved age-control. Information about age and timing of the closure have been derived from high-resolution biostratigraphy, palaeoenvironmental indicators, sediment transport directions, and the analysis of published onshore subsurface (core and seismic) datasets. We applied modern taxonomic concepts to revise the biostratigraphy of the Rifian Corridor and propose astronomically-tuned, minimum-maximum ages for its successions. Finally, we summarise the palaeogeographic evolution in four time slices corresponding to the middle Tortonian (10.57–8.37), late Tortonian (8.37–7.25 Ma), early Messinian (7.25–6.35 Ma), and late Messinian (6.35–5.33 Ma). Several successions record the closure of the corridor via a continuous marine to continental-lacustrine transition. The youngest dated marine sediments represent a good approximation of the age of seaway closure. The closure of the South Rifian Corridor is constrained to 7.1–6.9 Ma; that of the North Rifian Corridor is more uncertain and ranges from 7.35 to ca. 7 Ma. We conclude that the Rifian Corridor was already closed in the early Messinian and did not contribute to the restriction events that resulted in the MSC. Because the Betic Corridor is also closed by the early Messinian, the modern Gibraltar Straits remain the sole option in the Western Mediterranean as last Messinian seaway that was open during the MSC. Our results imply that the Gibraltar Straits could have been established as the exclusive Mediterranean-Atlantic portal already in the late Miocene, and therefore we suggest that future field and drilling campaigns should target the Alboran Sea and the Gibraltar region to investigate water exchange before and during the Messinian Salinity Crisis and its impact on Atlantic circulation and global climate.

  • paleoenvironmental evolution of the eastern mediterranean during the Messinian constraints from integrated microfossil data of the pissouri basin cyprus
    Marine Micropaleontology, 2006
    Co-Authors: T J Kouwenhoven, Wout Krijgsman, Caterina Morigi, A Negri, Simona Giunta, J M Rouchy
    Abstract:

    Abstract Integrated data of calcareous nannofossils, as well as planktonic and benthic foraminifera from the Pissouri Motorway section on Cyprus allow the reconstruction of surface- and bottom-water paleoenvironments of the eastern Mediterranean during the interval preceding the Messinian salinity crisis (MSC). Contrary to deeper-water locations, where benthic foraminifera faunas are suppressed or absent just after the Tortonian–Messinian boundary, sediments deposited at intermediate water depths do contain benthic assemblages. From the earliest Messinian onwards, a development towards increasingly unfavourable paleoenvironments is reflected in the planktonic and benthic microfossil records of the Pissouri section and proceeds with rather discrete time steps that can be correlated to sequences throughout the Mediterranean. Shortly after the Tortonian–Messinian boundary a transition is recorded in the sedimentology and the open marine, deeper-water taxa disappear from the benthic foraminifera assemblages; subsequently, the diversity of all fauna groups diminishes. The changes recorded at species level in both surface-water and sea-floor dwelling taxa suggest decreasing circulation of the bottom waters, associated with changes in the surface waters, most likely due to increasing stratification. From ∼6.73 Ma onwards, our data indicate a prominent change to more restricted conditions and increasing salinity at the sea floor together with intermittently rising surface water salinity. The dominance of oligotypic and monospecific assemblages and the frequent shifts in assemblage compositions of all microfossil groups indicate severely stressed environments after ∼6.4 Ma, probably related to increased salinity. The major changes in paleoenvironmental conditions, including oxygen deprivation due to stagnation and hypersalinity, can be explained by hydrographical changes in the Mediterranean basin, which are probably caused by tectonic movements in the Rif Corridor acting in concert with astronomical cyclicity. Evaluation of the paleodepth proxies indicates that the depth of the Pissouri Basin remained rather constant at ∼300–500 m, with a minimum of 200 m, until deposition of the “barre jaune”, the transitional interval towards the evaporites and that early shallowing to neritic depths, as was proposed before, is highly unlikely.

  • paratethyan mediterranean connectivity in the sea of marmara region nw turkey during the Messinian
    Sedimentary Geology, 2006
    Co-Authors: Namik M Cagatay, Wout Krijgsman, Rachel Flecker, Naci Gorur, Mehmet Sakinc, Cemal Tunoglu, R M Ellam, Stephen J Vincent, Aynur Dikbas
    Abstract:

    The Sea of Marmara region is thought to have been a gateway between Paratethys and the Mediterranean since the Middle Miocene, and is therefore an important control on water mass exchange between the two realms. The Miocene successions in the northeastern Aegean and northwestern Marmara regions indicate that the first Mediterranean marine transgression to affect these areas occurred during the late Serravallian. In the northeastern Aegean region, frequent marine incursions occurred during the Tortonian and Messinian stages. The Messinian stage in this area is represented by a package of brackish- to fresh-water carbonates with some marine sandstone–siltstone interbeds (Alcitepe Formation), which conformably overlies the Tortonian Kirazli Formation. The Messinian sequence is overlain with an erosional contact by a shallow marine siliciclastic sequence (Goztepe Formation) of Zanclean age. With its brackish- to fresh-water carbonates and broadly constrained age, the Messinian sequence is interpreted as being coeval with the Upper Evaporite–Lago Mare sequence observed in western Mediterranean basins. In the western Marmara region, the Pontian (Messinian) Alcitepe Formation consists of bioclastic and oolitic limestones with basal clastic rocks. It conformably overlies the fluvio-lacustrine siliciclastic sediments of the Middle to Upper Miocene Kirazli Formation and is overlain by fluvio-lacustrine sediments of the Kimmerian (5.5–3.2 Ma) Truva and Tevfikiye formations with an erosional contact. The bioclastic limestones of the Alcitepe Formation in the western Marmara region contain a molluscan and ostracod fauna that are endemic to Paratethys. These fauna indicate deposition in a shallow, brackish- to fresh-water environment. Faunal and paleomagnetic analyses of a section of the Alcitepe Formation at Yenimahalle (Canakkale) confirm that the formation is of Pontian age and represents chron C3r (6.04–5.24 Ma). The ostracod analysis indicates that during deposition of the Alcitepe Formation, salinity increased from brackish in the lower part to more saline conditions in the upper part. Ostracod valves have low 87Sr / 86Sr values relative to coeval Late Miocene ocean water. This indicates that exchange between the Sea of Marmara region and the global ocean was restricted throughout this period. Fossil and Sr-isotope evidence suggests, however, that there was a Paratethyan–Marmara connection during the deposition of the lower part of the Alcitepe Formation, with Paratethyan influence reaching the north Aegean. Connection via Marmara between Paratethys and the Mediterranean was not re-established until the late Aktchagylian (Late Pliocene). The re-connection was caused by both increased activity on the North Anatolian Fault and global sea level rise.

  • the Messinian of the nijar basin se spain sedimentation depositional environments and paleogeographic evolution
    Sedimentary Geology, 2003
    Co-Authors: A R Fortuin, Wout Krijgsman
    Abstract:

    Abstract The reconstruction of the depositional events related to the Messinian Salinity Crisis (MSC) of the Mediterranean is generally hampered by an incomplete stratal record in the circum-Mediterranean basins. The sediments of the northern part of the Nijar Basin, however, provide an excellent and continuous record of Late Messinian sediments because features of severe erosion are lacking. Especially, the successions of the deeper part of the basin had sufficient accommodation space to warrant ongoing deposition and may thus serve as a testing ground for existing hypotheses regarding the MSC. Conformable contacts with the overlying Pliocene and good correlation possibilities with the adjacent, astronomically dated, Messinian of the Sorbas Basin provide the necessary age constraints. The main body of evaporites in the Nijar Basin (Yesares Formation) has been affected by local dissolution and erosion prior to deposition of the latest Messinian (Lago–Mare) facies. Pelitic float breccias show textures indicating flowage and/or mass transport and include slumped and slided stratal packets due to foundering of the mixed evaporitic–clastic margin. Increased runoff of meteoric waters probably played an important role as these packet slides are perfectly sealed by the hyposaline Lago–Mare strata. Field observations show that marginal sediments, commonly classified as the Terminal Carbonate Complex (TCC), are a lateral equivalent of the basinal Yesares evaporites. The latest Messinian deposits (Feos Formation) are characterized by a sedimentary cyclicity, related to fluctuating base levels, consisting of chalky–marly laminitic strata alternating with continental coarser clastic intervals. Despite considerable W–E facies changes and indications for discrete tectonic events, a persistent sequential pattern of eight Lago–Mare cycles is present, which are interpreted as precession-controlled variations in regional climate. Instead of one major desiccation event in the latest Messinian, the repeatedly fluctuating water levels of the Lago–Mare episode may have been the cause of the widespread vigorous erosion and canyon cutting in the “Lower Evaporites”. Abrupt, non-erosional contacts with the normal marine Pliocene take place above the continental interval of the last Lago–Mare cycle, indicating that flooding took place during a period of lowered water levels. The paleogeographic configuration of the Nijar, Sorbas and Vera basins has changed considerably during the Messinian. Separation of the formerly interconnected basins is thought to have started in the late Yesares times by tectonic uplift of the basement complexes. In the latest Messinian of the Nijar Basin, two different coarse clastic supply areas can be distinguished which point to the partial emergence of the Sierra Cabrera and the Cabo de Gata block and activity of the Sierra Alhamilla and Carboneras faults. Concerning the overall regional tectonic activity, tectonics were probably also instrumental for the restoration of the Atlantic gateway in the basal Pliocene.

  • astrochronology for the Messinian sorbas basin se spain and orbital precessional forcing for evaporite cyclicity
    Sedimentary Geology, 2001
    Co-Authors: Wout Krijgsman, A R Fortuin, Frederik J Hilgen, Francisco Javier Sierro
    Abstract:

    The Sorbas basin of SE Spain contains one of the most complete sedimentary successions of the Mediterranean reflecting the increasing salinity during the Messinian salinity crisis. A detailed cyclostratigraphic study of these successions allows a correlation of the sedimentary cycle patterns to astronomical target curves. Here, we present an astrochronological framework for the Messinian of the central part of the Sorbas basin. This framework will form a solid basis for high-resolution correlations to the marginal carbonate facies and to the Central Mediterranean area. The early Messinian Abad Member contains 55 precession induced sedimentary cycles marked by homogeneous marl‐opalrich bed alternations in the ‘Lower Abad’ and by homogeneous marl‐sapropel alternations in the ‘Upper Abad’. Astronomical tuning results in an age of 5.96 Ma for the transition to the Yesares evaporites and thus for the onset of the ‘Messinian salinity crisis’. The marl‐sapropel cycles of the ‘Upper Abad’ are replaced by gypsum‐sapropel cycles (14) in the Yesares Member, indicating that the evaporite cyclicity is related to precession controlled oscillations in (circum) Mediterranean climate as well. As a consequence, gypsum beds correspond to precession maxima (insolation minima) and relatively dry climate, sapropelitic marls to precession minima (insolation maxima) and relatively wet climate. An alternative (glacio-eustatic) obliquity control for evaporite cyclicity can be excluded because the number of sedimentary cycles with a reversed polarity is too high. Sedimentation during the Abad, Yesares, and the overlying coastal sequences of the Sorbas Member, took place in a continuously marine environment, indicating that marine conditions in the Sorbas basin prevailed at least until 5.60‐5.54 Ma. According to our scenario, deposition of the Yesares and Sorbas Member took place synchronously with deposition of the ‘Lower Evaporites’ in the Central Mediterranean. Finally, the continental Zorreras Member consists of 8 sedimentary cycles of alternating reddish silts (dry climate) and yellowish sands (wet climate) which correlates very well with the ‘Upper Evaporites’ and Lago Mare facies of the Mediterranean. q 2001 Elsevier Science B.V. All rights reserved.

Joe Cartwright - One of the best experts on this subject based on the ideXlab platform.

  • The genesis of mud volcano conduits through thick evaporite sequences
    Basin Research, 2017
    Co-Authors: Chris Kirkham, Joe Cartwright, Christian Hermanrud, Christopher Jebsen
    Abstract:

    This study documents the seismic expression of the conduits underlying over 350 mud volcanoes that were erupted in an area of the western Nile Cone in the past 5.3 Myr. The study is based on a c. 4300 km2 3D seismic survey. The conduits are interpreted to transect the >1000-m-thick Messinian Evaporite succession, demonstrating that the eruptive process is sufficiently dynamic to breach the formidable seal represented by the evaporites. The mud volcano conduits are remarkably similar in geometry and seismic characteristics to many previously described examples of fluid escape pipes. They are vertical to subvertical structures with a crudely cylindrical geometry, but that can either widen or narrow upwards towards their upper terminations in the mud volcano edifices. Imaging at depth within the Messinian Evaporites and pre-evaporite successions is more uncertain, but direct sampling of mud from surface volcanoes suggests a pre-Messinian source, confirming the seismic interpretation that they root within presalt stratigraphy. A conceptual model for the genesis of these mud volcano conduits through salt is proposed, for which hydraulic fracturing is driven by high overpressures that developed in the presalt source stratigraphy as a response to the Messinian Salinity Crisis. Dissolution and removal of evaporites resulting in fracturing and collapse via a stoping mechanism is a slow process by comparison to hydraulic fracturing but is argued to potentially contribute to conduit formation. The analysis presented here demonstrates the potential for bypassing a >1-km-thick unit of sealing evaporites via focused fluid and sediment mobilisation from deeper overpressured cells in other salt basins worldwide, and has significant implications for hydrocarbon exploration, CO2 sequestration and nuclear waste disposal.

  • initiation of gravitational collapse of an evaporite basin margin the Messinian saline giant levant basin eastern mediterranean
    Geological Society of America Bulletin, 2008
    Co-Authors: Joe Cartwright, Martin P A Jackson
    Abstract:

    Regional 2D and 3D seismic data from the Levant Basin reveal the updip extensional component of thin-skinned gravity tectonics on this continental margin. Because of its youth (5–7 Ma), the earliest stages of deformation of this salt basin are preserved without the severe structural overprinting common on more mature, giant salt-tectonic systems. Extension detaches onto and within Messinian evaporites up to 1800 m thick. By structural restoration, we reconstruct the tectonic evolution of the Messinian evaporites using paleobathymetric constraints from wells and seismic profiles. This analysis suggests that the Mediterranean drawdown during the Messinian Salinity Crisis was ∼800 m. The 10- to 15-km–wide extensional domain tracks the landward pinch-out of the mobile Messinian evaporites against an older Late Miocene scarp. Diachronous extension began in the center of the margin in the mid-Pliocene, then spread northward in the late Pliocene, then finally southward in the early Pleistocene. Extension continues today on many of the most landward faults. Extensional strain varies greatly along strike from <1 km to as much as 12–15 km. Comparing observations with four end-member conceptual models, we infer that both extension and seaward salt flow thinned the evaporite margin and its overburden. Both processes were triggered by a combination of uplift of the continental shoulder of the Dead Sea Rift and subsidence in the Mediterranean Basin. At least three factors controlled variations in extension: (1) degree of tilting of the salt wedge, related to the interplay of coastal uplift and basin subsidence; (2) presence of pre-Messinian canyons overlain by landward salients of salt; and (3) variations in evaporite facies and the proportion of siliciclastic admixture.

  • major erosion at the end of the Messinian salinity crisis evidence from the levant basin eastern mediterranean
    Basin Research, 2007
    Co-Authors: Claudia Bertoni, Joe Cartwright
    Abstract:

    This paper presents a detailed analysis of the top of the Messinian evaporites (Horizon M) in the Levant region, offshore Israel, based on the integration of three-dimensional (3D)/2D seismic and well data. 3Dmapping of a series of intra-evaporite horizons and their termination against HorizonM provides new insights into the depositional setting and structural evolution of this saline giant system. New evidence of a discordant relationship between the intra-evaporite horizons and the top of theMessinian evaporites (HorizonM) is given by the seismic stratigraphic analysis. This confirms that the top of the Messinian evaporites represents an erosional unconformity of semiregional extent in the Levant region. The truncation of the folded and faulted intra- evaporite horizons indicates for the first time a Messinian phase of evaporite deformation, i.e. pre-dating the well-documented Plio- Pleistocene thin- skinned tectonic phase in the region. This major erosional unconformity is interpreted as subaerial in origin, documenting the exposure of the evaporitic systemat the end of the Messinian Salinity Crisis. These results give new evidence for the understanding of the events occurring during the last stages of the Messinian Salinity Crisis in the region.

  • controls on the basinwide architecture of late miocene Messinian evaporites on the levant margin eastern mediterranean
    Sedimentary Geology, 2006
    Co-Authors: Claudia Bertoni, Joe Cartwright
    Abstract:

    Abstract Interpretation of 2D and 3D seismic data from the Levant margin (Eastern Mediterranean) has revealed the complex depositional and structural setting of the basinwide late Miocene (Messinian) evaporites. The data set covers a total area of 20,000 km2, permitting a semi-regional investigation of the thick (up to 1.8 km) evaporitic wedge. The sequential analysis of time–structure maps, isochron maps and seismic cross-sections highlighted the main morphological and structural features characterizing the pre-, syn- and post-evaporitic Levant margin. This approach provided insights on the impact of local vs. regional factors in governing the distribution of the Messinian Salinity Crisis in the region. Two regional features have been recognized as the most significant controlling factors for the architecture of the Messinian evaporites. Firstly, a series of anticlines of the Syrian Arc foldbelt acted as a structural barrier indirectly governing the overall landward extension of the evaporites. Secondly, submarine canyons active in the area at least since the Oligocene (Afiq, El Arish and Ashdod Canyons) represented preferential sites of erosion and deposition of evaporites. Our results document therefore the importance of the deep-seated structures and relict drainage for the architecture of the Messinian evaporites on the Levant margin. The new insights provided can be additionally used to infer the original depositional geometry of the evaporites in the study area and as an analogue in other Mediterranean areas where 3D seismic is not available yet and sub-salt imaging is limited.

Lofi Johanna - One of the best experts on this subject based on the ideXlab platform.

  • Découverte de la surface d’érosion messinienne onshore/offshore dans deux lieux clés : le Promontoire Baléares (Ibiza) et la marge est-sarde (Orosei).
    'EDP Sciences', 2020
    Co-Authors: Maillard Agnès, Gaullier Virginie, Lezin Carine, Chanier Frank, Odonne Francis, Lofi Johanna
    Abstract:

    International audienceAs the Messinian sea-level draw down associated with the Messinian Salinity Crisis is still questioned, we propose to show that the widely spread erosion surface affecting the Mediterranean margins is indeed linked to an exondation demonstrated from offshore and onshore data. Our study presents a comprehensive onshore to offshore correlation of the Messinian erosional surface. It is focused on small drainage systems or interfluve areas, outside of evaporite basins or incised canyons, where the Messinian erosion had not yet been studied previously: around Ibiza on the Balearic Promontory and around Orosei on the Eastern Sardinian margin, Tyrrhenian Basin, both areas where new offshore data were recently acquired. We show that the late Messinian erosion formed in subaerial settings, as testified by evidence of continentalization events, and attests for a regression phase that was correlated from the offshore continental slopes to the onshore paleo-platforms in both areas. Characteristics of this erosion in both study areas strengthen the scenario with at least one important low-stand sea-level for the Messinian Salinity Crisis with evaporites subbasins lying at different depths and possibly disconnected.Depuis la découverte de la crise de salinité messinienne dans les années 70, le scénario proposant une chute importante du niveau marin associé à la mise en place des évaporites dans les plaines abyssales de la Méditerranée est régulièrement remis en cause. Nous montrons que la surface d'érosion affectant l'ensemble des marges est en effet liée à une émersion que l'on peut suivre à terre. Les observations présentées à terre s'attachent aux zones d'interfluves en dehors des bassins évaporitiques périphériques, là où la surface d'érosion messinienne n'a pas été étudiée : autour de l'île d'Ibiza dans les Baléares et autour d'Orosei sur la marge est-sarde. La surface d'érosion messinienne y est mise en évidence pour la première fois. Les données de sismique haute résolution récemment acquises dans ces deux zones nous permettent de présenter des corrélations terre-mer. Des évènements marquant clairement une continentalisation caractérisent la limite Mio-Pliocène dans les deux régions et atteste une phase régressive que l'on peut suivre des paléo-plateformes continentales à terre aux pentes du domaine offshore. Ces observations apportent des éléments pour étayer un scénario de la crise avec un bas niveau marin et des bassins évaporitiques à différentes paléo-bathymétries, possiblement déconnectés les uns des autres

  • The Messinian Salinity Crisis deposits in the Balearic Promontory: an undeformed analog of the MSC Sicilian basins??
    'Elsevier BV', 2020
    Co-Authors: Raad Fadl, Lofi Johanna, Maillard Agnès, Tzevahirtzian Athina, Caruso Antonio
    Abstract:

    International audienceThe Messinian Salinity Crisis (MSC) is a controversial geological event that influenced the Mediterranean Basin in the late Miocene leaving behind a widespread Salt Giant. Today, more than 90% of the Messinian evaporitic deposits are located offshore, buried below the Plio-Quaternary sediments and have thus been studied mainly by marine seismic reflection imaging. Onshore-offshore records’ comparisons and correlations should be considered a key approach to progress in our understanding of the MSC.This approach has however not been widely explored so far. Indeed, because of the erosion on the Messinian continental shelves and slopes during the MSC, only few places in the Mediterranean domain offers the opportunity to compare onshore and offshore records that have been preserved from erosion. In this paper, we compare for the first time the MSC records from two basins that were lying at intermediate water depths during the MSC and in which salt layers emplaced in topographic lows: the Central Mallorca Depression (CMD) in the Balearic Promontory, and the Caltanissetta Basin (CB) in Sicily. The reduced tectonic movements in the CMD since the late Miocene (Messinian) till recent days, favored the conservation of most of the MSC records in a configuration relatively close to their original configuration, thus allowing a comparison with the reference records outcropping in Sicily. We perform seismic interpretation of a wide seismic reflection dataset in the study area with the aim of refining the mapping of the Messinian units covering the Balearic Promontory (BP) and restituting their depositional history based on a detailed comparison with the Messinian evaporitic units of the Sicilian Caltanissetta Basin. We discuss how this history matches with the existing 3-stages chrono-stratigraphic model. We show that the Messinian units of Central Mallorca Depression could be an undeformed analog of those outcropping on-land in the Sicilian Caltanissetta Basin, thus questioning the contemporaneous onset of the salt deposition on the Mediterranean scale. We show a change in seismic facies at a certain range of depth between stage 1 MSC units, and wonder if this could reflect the threshold/maximum depth of deposition of bottom growth PLG selenites passing more distally to pelagic snowfall cumulate gypsum. Moreover, we confirm that PLG could be deposited in water depths exceeding 200m

  • New onshore/offshore evidence of the Messinian Erosion Surface from key areas: The Ibiza-Balearic Promontory and the Orosei-Eastern Sardinian margin
    'EDP Sciences', 2020
    Co-Authors: Maillard Agnès, Gaullier Virginie, Lezin Carine, Chanier Frank, Odonne Francis, Lofi Johanna
    Abstract:

    As the Messinian sea-level draw down associated with the Messinian Salinity Crisis is still questioned, we propose to show that the widely spread erosion surface affecting the Mediterranean margins is indeed linked to an exondation demonstrated from offshore and onshore data. Our study presents a comprehensive onshore to offshore correlation of the Messinian erosional surface. It is focused on small drainage systems or interfluve areas, outside of evaporite basins or incised canyons, where the Messinian erosion had not yet been studied previously: around Ibiza on the Balearic Promontory and around Orosei on the Eastern Sardinian margin, Tyrrhenian Basin, both areas where new offshore data were recently acquired. We show that the late Messinian erosion formed in subaerial settings, as testified by evidence of continentalization events, and attests for a regression phase that was correlated from the offshore continental slopes to the onshore paleo-platforms in both areas. Characteristics of this erosion in both study areas strengthen the scenario with at least one important low-stand sea-level for the Messinian Salinity Crisis with evaporites subbasins lying at different depths and possibly disconnected.Depuis la découverte de la crise de salinité messinienne dans les années 70, le scénario proposant une chute importante du niveau marin associé à la mise en place des évaporites dans les plaines abyssales de la Méditerranée est régulièrement remis en cause. Nous montrons que la surface d’érosion affectant l’ensemble des marges est en effet liée à une émersion que l’on peut suivre à terre. Les observations présentées à terre s’attachent aux zones d’interfluves en dehors des bassins évaporitiques périphériques, là où la surface d’érosion messinienne n’a pas été étudiée : autour de l’île d’Ibiza dans les Baléares et autour d’Orosei sur la marge est-sarde. La surface d’érosion messinienne y est mise en évidence pour la première fois. Les données de sismique haute résolution récemment acquises dans ces deux zones nous permettent de présenter des corrélations terre-mer. Des évènements marquant clairement une continentalisation caractérisent la limite Mio-Pliocène dans les deux régions et atteste une phase régressive que l’on peut suivre des paléo-plateformes continentales à terre aux pentes du domaine offshore. Ces observations apportent des éléments pour étayer un scénario de la crise avec un bas niveau marin et des bassins évaporitiques à différentes paléo-bathymétries, possiblement déconnectés les uns des autres

  • Discovery of vast fluvial deposits provides evidence for drawdown during the late Miocene Messinian salinity crisis
    'Geological Society of America', 2019
    Co-Authors: Madof, Andrew S., Bertoni Claudia, Lofi Johanna
    Abstract:

    International audienceThe late Miocene Messinian salinity crisis (MSC) was a significant oceanographic event that caused widespread evaporitic accumulation throughout the Mediterranean Basin. Although multiple hypotheses exist regarding the origin of evaporitic and post-evaporitic deposits, researchers remain divided on the magnitude of base-level fall, and on whether these accumulations record deep-water or non-marine conditions. Here, we introduce a previously unknown, upper Messinian fluvial deposit comparable in size to the late Miocene Nile River fluvial valley fill and show that near-complete desiccation of the eastern Mediterranean was responsible for its development. The basin-wide accumulation, which is located offshore Cyprus, Syria, Lebanon, and Israel, lies directly atop deep-basin evaporites and related erosional surfaces, and is one of the largest known riverine deposits associated with the terminal MSC. From marked onshore incision and basinward thinning trends, the source of the accumulation is presumed to be a formerly unidentified drainage basin in southern Turkey and western Syria; the deposit extends > 500 km into the western Levant Basin, where its depositional sink is marked by six well-developed backstepping lobes. Based on the deposit's seismic stratigraphy and morphology, which provide clear evidence of subaerial exposure, we question current hypotheses proposing a deepwater origin for late Messinian accumulations. We also draw specific attention to the development of extensive circum-Mediterranean nonmarine conditions prior to Zanclean marine transgression, and to the previously overlooked role of fluvial systems in diluting hypersaline lakes in evaporitic basins

Jean-jacques Cornee - One of the best experts on this subject based on the ideXlab platform.

  • Ages and stratigraphical architecture of late Miocene deposits in the Lorca Basin (Betics, SE Spain): New insights for the salinity crisis in marginal basins
    Sedimentary Geology, 2020
    Co-Authors: Cédric Carpentier, Jean-jacques Cornee, Emmanuelle Vennin, Jean-marie Rouchy, Mihaela Melinte-dobrinescu, Christian Hibsch, Nicolas Olivier, Antonio Caruso, Danièle Bartier
    Abstract:

    Unlike most Neogene basins of the Betic Cordillera where the Salinity Crisis is dated to the Messinian, a contradictory Tortonian dating was proposed for evaporites of the Lorca Basin. As a consequence, complex structural models have been proposed in the literature to explain this discrepancy in the timing of evaporites. In order to integrate the Lorca Basin into the geological context of the western Mediterranean domain during the Late Miocene, new sedimentological and stratigraphical studies coupled with new dating were performed, which allow us to propose a Messinian age for both diatomite-bearing deposits and evaporites of the Lorca Basin. These new ages challenge the idea of a Tortonian salinity crisis in the Lorca Basin. Three main events of base-level drop were evidenced during the Messinian. Each event is correlated with successive steps of basin restriction. Shallow salina evaporites were deposited after a base-level fall during the Messinian before a final base-level drop, which led to the entire exposure of the basin. This last exposure is interpreted as coeval with the deposition of first evaporites and halite in the deep Mediterranean basins. The reflooding which allowed the deposition of brackish deposits and a short-lived marine incursion occurred at the end of the Messinian. Base-level drops occurred during eustatic falls amplified by the gradual uplift of the Betic Cordillera. The exhumation of the Tercia ridge along the strike-slip Alhama de Murcia fault system during the Messinian probably favoured the gradual restriction of the basin. A discussion on correlations of main unconformities between several Neogene basins of the Betics is proposed, suggesting a similar structural evolution at the regional scale.

  • palaeoenvironmental changes at the tortonian Messinian boundary a deep sea sedimentary record of the eastern mediterranean sea
    Palaeogeography Palaeoclimatology Palaeoecology, 2018
    Co-Authors: Pierre Moissette, Jean-jacques Cornee, Efterpi Koskeridou, Assimina Antonarakou, George Kontakiotis, Hara Drinia, Theodora Tsourou, Konstantina Agiadi, V Karakitsios
    Abstract:

    Abstract In the eastern Mediterranean, the island of Crete offers excellent exposures of upper Miocene marine deposits. Three detailed sections of the Tortonian/Messinian sedimentary succession were measured and sampled in three different basins (from west to east: Chania, Heraklion, and Sitia). The biostratigraphic analysis based on planktonic foraminifera yielded ages ranging from about 7.58 to 6.72 Ma. Nine bioevents were also recognised and provided good correlations between the studied sections. Rich benthic faunas (commonly occurring together with fish otoliths) have furthermore been recovered and analysed: foraminifera, mollusc (mostly bivalves), bryozoans, and ostracods. The autochthonous assemblages suggest deposition at middle-upper bathyal depths at the base and outer-inner shelf in the upper parts of the sections. The shallowing upward trend observed in all three sections is accompanied by the occurrence in a few Messinian levels of allochthonous fossils transported downslope and deposited in deep-water environments. Dysoxic episodes were moreover recorded in some beds, mostly in the Messinian. A comparison with other coeval basins and faunas indicates that similar palaeoenvironmental conditions predominated throughout the Mediterranean Sea during the late Miocene. This is consistent with the postulate of open connections (through marine corridors) between the Mediterranean and the Atlantic, presumably until late in the Messinian.

  • The western edge of the Mediterranean Pelagian Platform: A Messinian mixed siliciclastic-carbonate ramp in northern Tunisia
    Palaeogeography Palaeoclimatology Palaeoecology, 2010
    Co-Authors: Pierre Moissette, Jean-jacques Cornee, Beya Mannai-tayech, Mohsen Rabhi, Jean-pierre Andre, Efterpi Koskeridou, Henriette Meon
    Abstract:

    The marine Messinian deposits of Tunisia cover a narrow littoral strip some 300 km long between the northern Bizerte and Cap Bon areas and the central-eastern Sahel region. Litho- and biofacies analysis of six stratigraphic sections reveals the distinctive features of these deposits.;The lower Messinian deposits are characterized by ubiquitous siliciclastics and abundant oolitic/bioclastic limestones organized in an eastward facing ramp. Westward (landward), this ramp changes into coastal lagoons, sometimes containing evaporites. Eastward, the ramp passes to the reefal Pelagian Platform extending as far as Lampedusa.;Two main sedimentary cycles are distinguished: 1) an early Messinian siliciclastic retrogradational then oolitic/bioclastic progradational cycle (Beni Khiar Formation and lower Oued bel Khedim Formation): 2) a late Messinian brackish to continental cycle that probably accumulated in rapidly subsiding lagoons (Cued el Bir Formation and upper Oued bel Khedim Formation). The Tunisian early Messinian cycle is partly eustatically controlled, but the late Messinian cycle cannot be confidently correlated to other well-known Messinian series because of tectonic movements.;The lower Messinian deposits of Tunisia are also characterized by abundant suspension-feeding organisms (molluscs and bryozoans) and rare corals, calcareous algae, echinoids, and larger benthic foraminifers. The proposed palaeoenvironmental model shows that the lower Messinian ramp of Tunisia was located on a current-protected margin and subjected to continent-derived sediment and nutrient supply. Eastward, nutrient influx diminished and a shallow-water isolated carbonate platform with coralgal facies developed between the western and the eastern Mediterranean basins. The main hydrological connection between these two basins occurred through a narrow seaway situated to the northeast of the Pelagian Platform, south of Sicily and Malta.

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  • Le Néogène du bassin Guercif-Taourirt (Maroc oriental) : Paléoenvironnement, caractérisation et potentiel de valorisation des Argiles
    Université Mohammed Premier ​Oujda ​​Maroc, 2020
    Co-Authors: Amakrane Jemaa
    Abstract:

    The Neogene Guercif-Taourirt Basins, located in the South Rifain Corridor (Morocco), includes large marl-clay deposits. These deposits were studied using a micro-paleontological (planktonic and benthic foraminifera) and mineralogical (clays) approach in order to reconstruct the evolution of palaeoenvironmental conditions over the late Miocene. In addition, the economic interest of this mixed sedimentation was evaluated for ceramic applications. The Neogene sedimentation of the Guercif-Taourirt basins, covers the late Miocene deposits to the Pliocene. Five lithological units observed in the studied sections of the Guercif basin. The Neogene sedimentation begins by conglomerate-marl continental deposits (Draa Sidi Saada unit) followed by Tortonian marine deposits (calcareniticsmarls of the Ras El Ksar unit, blue marl subunit and sandstone-marl subunit). The whole Tortonian marine deposits represent a transgressive sequence, followed by regressive deposits made by gypsiferous marls. These are capped by the transitional regressive sandstone-marl deposits of the Messinian Kef Ed Deba unit and then by the continental Pliocene deposits of unit Bou Irhardaiene. In the sections of the Taourirt basin, three lithological units were identified, based on the Zobzit-Safsafat composite section. The sedimentary record begins by green marl unit (equivalent to the blue marls subunit of the Tortonian), followed by the sandstone-marl unit (equivalent to the gypsiferous marls subunit of the Messinian). The unit represented by the alternation of sandstone, sand and laminated clays represents a partial equivalent of the Kef Ed Deba unit of the Messinian. These are surmounted by conglomerates of the Plio-Quaternary Bou Irhardaiene unit. The chronostratigraphical data allow to reconstruct the evolution of the South Rifain Corridor over the late Miocene. The marine deposits were deposited between the Middle/Late Tortonian and Early Messinian in the Guercif basin and Late Tortonian to Early Messinian in the Taourirt basin. The main change in the planktonic foraminifera assemblages defines the transition and lithostratigraphical continuity between Late Tortonian and Messinian in the Guercif-Taourirt basins. The benthic foraminifera associations evidence an evolution of the sedimentary environments of the upper Miocene deposits of the Guercif basin, with a gradual deepening of the basin. For the basal deposits of Middle and Late Tortonian, the micropaleontological content revealed species of infralittoral towards circalittoral environment. The environment gradually changes to epibathiyal conditions observed for upper Tortonian deposits where the transgression reaches its maximum. At the Tortonian/Messinian boundary (7,24 Ma), the sedimentation environment returns back to circalittoral in relation to the rapid shrinking of the South Rifain Corridor. Synchronously clay-rich Tortonian marls were deposited in the Taourirt basin. During the Messinian, a decrease of bathymetry is observed, with a transition from a circalittoral to a infralittoral environment. The emergence of the basin occurs at the end of the Messinian (ca. 6.1 Ma) with the closure of the South Rifain Corridor. This event initiates the Messinian Salinity Crisis. The analysis of clay associations indicates a mineralogical diversity conditioned by contemporary paleogeographic factors, with no diagenetic influence. The clay fraction is characterized by the presence of illite, chlorite, palygorskite, smectite, kaolinite and interstratified illite-smectite. At the scale of the basin, the appearance of palygorskite during upper Tortonian and its presence over the Messinian indicate evaporitic conditions. According to their mineralogical and geotechnical properties, the Tortonian and Messinian sediments of the Guercif basin and the Tortonian sediments of the Taourirt basin belong to the common clays type. These clays can be applied in ceramic industry, especially as building materials. However the valorization of these sediments as fired bricks requires pretreatments (i.e., crushing and carbonate elimination). In the Taourirt basin, the Messinian sediments and gray bentonite can both be used as clay barriers in landfill sites, taking into account the requirements and criteria recommended in this field.Bourse Erasmus plus-Belgique; Bourse d'état pour la recherche scientifique et technique-Maro

  • Le Néogène du bassin Guercif-Taourirt (Maroc oriental) : Paléoenvironnement, caractérisation et potentiel de valorisation des Argiles
    Université Mohammed Premier ​Oujda ​​Maroc, 2020
    Co-Authors: Amakrane Jemaa
    Abstract:

    The Neogene Guercif-Taourirt Basins, located in the South Rifain Corridor (Morocco), includes large marl-clay deposits. These deposits were studied using a micro-paleontological (planktonic and benthic foraminifera) and mineralogical (clays) approach in order to reconstruct the evolution of palaeoenvironmental conditions over the late Miocene. In addition, the economic interest of this mixed sedimentation was evaluated for ceramic applications. The Neogene sedimentation of the Guercif-Taourirt basins, covers the late Miocene deposits to the Pliocene. Five lithological units observed in the studied sections of the Guercif basin. The Neogene sedimentation begins by conglomerate-marl continental deposits (Draa Sidi Saada unit) followed by Tortonian marine deposits (calcareniticsmarls of the Ras El Ksar unit, blue marl subunit and sandstone-marl subunit). The whole Tortonian marine deposits represent a transgressive sequence, followed by regressive deposits made by gypsiferous marls. These are capped by the transitional regressive sandstone-marl deposits of the Messinian Kef Ed Deba unit and then by the continental Pliocene deposits of unit Bou Irhardaiene. In the sections of the Taourirt basin, three lithological units were identified, based on the Zobzit-Safsafat composite section. The sedimentary record begins by green marl unit (equivalent to the blue marls subunit of the Tortonian), followed by the sandstone-marl unit (equivalent to the gypsiferous marls subunit of the Messinian). The unit represented by the alternation of sandstone, sand and laminated clays represents a partial equivalent of the Kef Ed Deba unit of the Messinian. These are surmounted by conglomerates of the Plio-Quaternary Bou Irhardaiene unit. The chronostratigraphical data allow to reconstruct the evolution of the South Rifain Corridor over the late Miocene. The marine deposits were deposited between the Middle/Late Tortonian and Early Messinian in the Guercif basin and Late Tortonian to Early Messinian in the Taourirt basin. The main change in the planktonic foraminifera assemblages defines the transition and lithostratigraphical continuity between Late Tortonian and Messinian in the Guercif-Taourirt basins. The benthic foraminifera associations evidence an evolution of the sedimentary environments of the upper Miocene deposits of the Guercif basin, with a gradual deepening of the basin. For the basal deposits of Middle and Late Tortonian, the micropaleontological content revealed species of infralittoral towards circalittoral environment. The environment gradually changes to epibathiyal conditions observed for upper Tortonian deposits where the transgression reaches its maximum. At the Tortonian/Messinian boundary (7,24 Ma), the sedimentation environment returns back to circalittoral in relation to the rapid shrinking of the South Rifain Corridor. Synchronously clay-rich Tortonian marls were deposited in the Taourirt basin. During the Messinian, a decrease of bathymetry is observed, with a transition from a circalittoral to a infralittoral environment. The emergence of the basin occurs at the end of the Messinian (ca. 6.1 Ma) with the closure of the South Rifain Corridor. This event initiates the Messinian Salinity Crisis. The analysis of clay associations indicates a mineralogical diversity conditioned by contemporary paleogeographic factors, with no diagenetic influence. The clay fraction is characterized by the presence of illite, chlorite, palygorskite, smectite, kaolinite and interstratified illite-smectite. At the scale of the basin, the appearance of palygorskite during upper Tortonian and its presence over the Messinian indicate evaporitic conditions. According to their mineralogical and geotechnical properties, the Tortonian and Messinian sediments of the Guercif basin and the Tortonian sediments of the Taourirt basin belong to the common clays type. These clays can be applied in ceramic industry, especially as building materials. However the valorization of these sediments as fired bricks requires pretreatments (i.e., crushing and carbonate elimination). In the Taourirt basin, the Messinian sediments and gray bentonite can both be used as clay barriers in landfill sites, taking into account the requirements and criteria recommended in this field