Le déluge et la Crise messinienne

National audienceLa Crise messinienne débuta il y a 5,971 Millions d’années (Ma) pour s’achever 500 000 ans plus tard. L’eau, qu’elle soit salée, saumâtre ou douce, y a tenu un rôle déterminant. La fin de crise s’est soldée par un déluge d’une violence inouïe tirant sa source dansl’ampleur même de la crise, à savoir l’évaporation quasi-totale de la Mer Méditerranée. Depuis 14 Ma, la Méditerranée est un appendice de l’Océan Atlantique. La tectonique a fermé successivement trois corridors pour n’en laisser qu’un seul au sud du Rif (figure 1a-b). Les stades de la Crise messinienne sont bien datés par les microfossiles marins, le paléomagnétisme, la cyclostratigraphie

The GOLD project - Drilling in the Western Mediterranean Sea

ECORD NEWSLETTER 16The "GOLD" IODP Project aims to recover the complete history of the Gulf of Lion (25-30 Ma) with a specific focus on Global Climate and Sea-level Changes, Extreme Events, Margin formation, Natural Resources and the Deep Biosphere using dedicated drilling Platform (MSP, Joides and Chikyu). It should be emphasized that no academic drillings dealing with pre-5million years exist in the Mediterranean Sea

The Late Palaeozoic glaciation subsurface record, Chaco Basin (Bolivia)

Late Palaeozoic glaciation is the longest of the Phanerozoic era. It is recorded in numerous Gondwanian basins, some having a high petroleum potential like the Chaco Basin. In this basin, the quality of the available seismic, well and outcrop data permits to characterise the Late Palaeozoic glacial record. Palaeovalleys >500 m deep and ~7 km wide have here been analysed. Focusing on the glaciogenic Carboniferous deposits, the seismic data with well-ties and their outcrop analogues provide new sedimentological insights. The palaeovalley infill is imaged as a chaotic seismic facies overlain by an aggrading-prograding prism, interpreted as tillites covered by a fluvio-deltaic system respectively. Tillites form both under the ice and during rapid ice recession whereas fluvio-deltaic systems can only originate from a stable ice margin and last until the ice sheets withdraw inland. These two depositional modes are repeated several times generating the progressive burial of the Carboniferous palaeovalleys. This succession of erosions and fills records major glacial stages containing a series of glacial and interglacial phases from the Late Devonian to the Early Permian. Depicting the Late Palaeozoic glacial history of the Chaco Basin seems crucial for the localisation of potential good reservoirs

The two-stage aegean extension, from localized to distributed, a result of slab rollback acceleration

International audienceBack-arc extension in the Aegean, which was driven by slab rollback since 45 Ma, is described here for the first time in two stages. From Middle Eocene to Middle Miocene, deformation was localized leading to i) the exhumation of high-pressure metamorphic rocks to crustal depths, ii) the exhumation of high-temperature metamorphic rocks in core complexes and iii) the deposition of sedimentary basins. Since Middle Miocene, extension distributed over the whole Aegean domain controlled the deposition of onshore and offshore Neogene sedimentary basins. We reconstructed this two-stage evolution in 3D and four steps at Aegean scale by using available ages of metamorphic and sedimentary processes, geometry and kinematics of ductile deformation, paleomagnetic data and available tomographic models. The restoration model shows that the rate of trench retreat was around 0.6 cm/y during the first 30 My and then accelerated up to 3.2 cm/y during the last 15 My. The sharp transition observed in the mode of extension, localized versus distributed, in Middle Miocene correlates with the acceleration of trench retreat and is likely a consequence of the Hellenic slab tearing documented by mantle tomography. The development of large dextral NE-SW strike-slip faults, since Middle Miocene, is illustrated by the 450 Km-long fault zone, offshore from Myrthes to Ikaria and onshore from Izmir to Balikeshir, in western Anatolia. Therefore, the interaction between the Hellenic trench retreat and the westward displacement of Anatolia started in Middle Miocene, almost 10 Ma before the propagation of the North Anatolian Fault in the North Aegean

Messinian erosional and salinity crises: View from the Provence Basin (Gulf of Lions, Western Mediterranean)

International audienceThough the late Miocene “Messinian Salinity Crisis” has been intensely researched along the circum-Mediterranean basins, few studies have focused on the central part of the Mediterranean Basin and, especially, the pre-salt deposits. To improve our knowledge of the Messinian events, it is imperative to better understand this domain. In this study, we provide a more complete understanding of this central domain in the Provence Basin. We were able to recognize: a) thick marine detrital series (up to 1000 m) derived from the Messinian subaerial erosion which is partly prolongated in the distal part by b) a thick unit of deep marine deposits (up to 800 m) prior to the evaporites; c) a thick presumed alternation of detritals and evaporites (1500 m) below the mobile halite; and d) a two-step transgression at the end of the Messinian. Spatially, we document the eroded shelf to the deep basin (and from the western to the eastern parts of the Gulf of Lions), and temporally, we extend the interpretations from the early deposition of detritic sediments to the final sea-level rise. The results provide a new basis for discussion not only for the development of the Messinian Salinity Crisis but also for the reconstruction of the subsidence history of the Provence Basin

Post-rift uplift of the Dhofar margin (Gulf of Aden)

International audienceAn investigation of the sedimentation pattern along the Dhofar margin allows us to describe its late-stage evolution. After the accumulation of a thick post-rift sedimentary succession, two debris flow events occurred at the foot of the slope. The first event, affecting a wide area of the margin, marks a major change in sedimentation. The second event is associated with a shift of sedimentary deposition from the slope toward the basin. This latter debris flow was caused by an uplift phase, and highlights two distinct deformational styles in the eastern and western part of the Dhofar margin. Both events occurred very late in the history of the margin, at least 7.6 Ma after the end of the rifting phase (35-17.6 Ma)

Lago Mare and the Messinian Salinity Crisis: Evidence from the Alboran Sea (S. Spain)

International audienceThis paper provides a new environmental, sedimentological and stratigraphic context of the Lago Mare deposits from the North Alboran region and clarifies their chronologic location with respect to the Messinian Salinity Crisis. We present new micropaleontological data (dinoflagellate cysts, calcareous nannoplankton, planktonic foraminifers), correlated with field observations and offshore seismic interpretations. We show that the Lago Mare event known in three onshore localities (Río Mendelín near Malaga, Zorreras near Sorbas, Gafares near Níjar) follows the marine reflooding of the Mediterranean Basin which ended the Messinian Salinity Crisis. Chronologically, these Lago Mare deposits last from the latest Messinian to the early Zanclean. In fact, the first influx of Paratethyan- organisms is revealed by the dinoflagellate cyst record from near Malaga within a Gilbert-type fan delta overlying the Messinian Erosional Surface. Invading molluscs and/or ostracods may have persisted in lagoonal coastal areas more or less affected by discontinuous marine influxes (Sorbas and Níjar). The Malaga area is convenient for a paleogeographic and sedimentary reconstruction which shows the prevalent forcing of sea level changes during the time-interval 5.600-5.332 Ma at the difference of the usually solicited prevalent tectonics. The studied Lago Mare event is the third episode resulting in such a paleobiological assemblage in the Mediterranean region and corresponds to the final two-way water exchange at high sea level between the Mediterranean and the former Paratethys. It documents the onset of the modern marine circulation in the Mediterranean after the reflooding ending the Messinian Salinity Crisis

Interacción entre procesos sedimentarios longitudinales y transversales en el Mar de Alborán durante el Plioceno y Cuaternario

Several morphosedimentary signatures produced by the interaction between alongslope and downslope sedimentary processes have been identified in the Pliocene and Quaternary records as well as on the present-day seafloor of the Alboran Sea. The scenarios of interaction move between two-end-members: from bottom currents dominating gravity flows to gravity flows dominating contour currents. In between these extreme cases, the alternation and balancing of both processes can occur; bottom current activity influencing the gravity flows has been also detected. Although interaction occurs in the Spanish and Moroccan margins, it is especially complex and varied on the Spanish margin, with regional and local effects on the turbidite systems. In contrast, the interaction on the Moroccan margin primarily inhibits the formation of canyons and related fan lobe deposits.Versión del edito

Psychological couple-oriented interventions for patients with heart disease and their partners: a scoping review and guidelines for future interventions

ObjectiveThis scoping review aims to provide an accessible summary of available evidence on the efficacy of psychological couple-based interventions among patients with heart disease and their partners focusing on specific aspects and strategies by assessing different emotional and physical cardiac-related outcome measures.MethodsA literature search was performed in PubMed, Scopus, Medline, PsycINFO, and Web of Science databases using the keywords “heart diseases” and “couple-based intervention.” A literature search using systematic methods was applied. Data were extracted to address the review aims and were presented as a narrative synthesis.ResultsThe database search produced 11 studies. Psychological couple-based interventions varied in terms of the type of intervention, personnel, format (group or individual, phone or in person), number of sessions, and duration. Most of the contributions also lacked adequate details on the training of professionals, the contents of the interventions, and the theoretical models on which they were based. Finally, although partners were involved in all the treatment, in most studies, the psychological strategies and outcomes were focused on the patient.ConclusionThe variability of the psychological couple-based interventions of included studies represents a challenge in summarizing the existing literature. Regarding their impact, psychological interventions for patients with cardiovascular disease and their partners were found to moderately improve patients’ and partners’ outcomes