Karstic Geomorphology of Carbonate Ouarsenis Piedmont (Boukadir Region, Chelif) in Algeria: The Role of the Messinian Salinity Crisis

2021 ◽  
Author(s):  
Meriem Lina MOULANA ◽  
Aurélia Hubert Ferrari ◽  
Mostefa Guendouz ◽  
Sébastien Doutreloup ◽  
Sarah Robinet ◽  
...  
Keyword(s):  
Messinian Salinity Crisis

A scale-independent model for land-locked seas with application to the Messinian salinity crisis

2020 ◽  
Author(s):  
Paul Meijer
Keyword(s):  
Mediterranean Sea ◽  
Independent Solution ◽  
Aegean Sea ◽  
Basic Element ◽  
Messinian Salinity Crisis ◽  
Elevated Salinity ◽  
Levantine Basin ◽  
The Mediterranean ◽  
Atmospheric Heat

<p>While the Mediterranean Sea is, since the Middle Miocene, a nearly completely land-locked basin indeed, it is itself comprised of several smaller semi-enclosed seas. What the Mediterranean Sea as a whole is to the Atlantic Ocean, are the Adriatic Sea or Aegean Sea to the Ionian-Levantine basin, for example. In the discussions regarding the Messinian salinity crisis the marginal basins of the Mediterranean play a prominent role because it is from these parts that the sedimentary record has been uplifted and become exposed.</p><p>In view of this and with an aim to contribute insight from the field of modelling, we focus on the basic element: a single marginal basin, subject to atmospheric forcing and exchanging water through a seaway with an adjacent larger basin. The equations are derived in dimensionless form and a universal, scale-independent, solution for basin salinity obtained. The analysis yields two dimensionless ratios which control basin behaviour in terms of salinity and response time. </p><p>Application of the theoretical model to the Messinian salinity crisis sheds new light on the formation of gypsum in marginal basins that were separated from the main Mediterranean by a sill, gives insight about the role of atmospheric heat exchange, and underlines the previous finding that, at elevated salinity, marginal basins respond to periodic climate variation (e.g. due to precession) with a significant lag.</p>

The role of isostatic adjustment and gravitational effects on the dynamics of the Messinian salinity crisis

2019 ◽  
Vol 525 ◽  
pp. 115760 ◽  
Author(s):  
Sophie Coulson ◽  
Tamara Pico ◽  
Jacqueline Austermann ◽  
Evelyn Powell ◽  
Robert Moucha ◽  
...  
Keyword(s):  
Messinian Salinity Crisis ◽  
Gravitational Effects ◽  
Isostatic Adjustment

Microbial sulfur cycling during the formation of Primary Lower Gypsum in Mediterranean marginals basins

2021 ◽  
Author(s):  
Laetitia Guibourdenche ◽  
Pierre Cartigny ◽  
Francesco Dela Pierre ◽  
Marcello Natalicchio ◽  
Giovanni Aloisi
Keyword(s):  
Isotopic Composition ◽  
Sulfur Cycling ◽  
Messinian Salinity Crisis ◽  
Sulfate Ion ◽  
Reduced Sulfur Compounds ◽  
Sulfur Isotopic Composition ◽  
Microbial Sulfate Reduction ◽  
Gypsum Formation ◽  
Wide Range

<p>During the first phase of the Messinian Salinity Crisis, massive amounts of sulfate (SO<sub>4</sub><sup>2-</sup>) have been sequestred in the form of up to 200m thick gypsum deposits (Primary Lower Gypsum) in Mediterranean marginal basins. The sulfur isotopic composition of the sulfate ion of this unit (δ<sup>34</sup>S<sub>SO4</sub>) (on average 22.3 ‰) strongly suggests that gypsum was formed by concentration of marine sulfate. Interestingly, the preservation of sulfide globules within the gypsum and marls interbeds suggests that the basin sulfate was not only involved in gypsum formation but a fraction was also reduced through microbial sulfate reduction. Moreover, filamentous fossils interpreted to be the remnants of sulfide oxidizing bacterias are entrapped in this gypsum and indicate, together with the occurrence of sulfide globules and dolomite, that an active biogeochemical sulfur cycling was active at the time of Primary Lower Gypsum deposition. To investigate the role of this active sulfur cycling in Mediterranean marginal basins, we analyzed the multiple sulfur isotopic composition of sulfate and sulfide minerals (δ<sup>34</sup>S andΔ<sup>33</sup>S)<sub></sub>from Primary Lower Gypsum of the Vena del Gesso basin (Italy). Whereas the isotopic composition of gypsum (δ<sup>34</sup>S<sub>SO4 </sub>from 21 to 24‰ and Δ<sup>33</sup>S<sub>SO4 </sub>from -0.001 to 0.049‰) display very homogenous values that are close to those of the Messinian ocean (δ<sup>34</sup>S<sub>MSC </sub>~22±0.2‰ and Δ<sup>33</sup>S<sub>MSC</sub>~0.039±0.015), the analyzed reduced sulfur compounds display a wide range of variability  with -36 to +9‰ in δ<sup>34</sup>S and -0.017 to 0.125‰ in Δ<sup>33</sup>S. This suggests huge hydrologically-driven redox variations during Primary Lower Gypsum deposition in the Vena del Gesso basin, possibly involving intermittent stratification of the water column and an active microbial cycling of sulfur.</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>

scholarly journals Modelling the vertical motions of the Alboran Sea since the Messinian salinity crisis: Topographic reconstruction and glacial-isostatic sea-level effects 

2021 ◽  
Author(s):  
Hanneke Heida ◽  
Daniel Garcia-Castellanos ◽  
Ivone Jiménez-Munt ◽  
Ferran Estrada ◽  
Gemma Ercilla ◽  
...  
Keyword(s):  
Sea Level ◽  
Potential Role ◽  
Messinian Salinity Crisis ◽  
Sea Level Changes ◽  
Strait Of Gibraltar ◽  
Spatial And Temporal Scales ◽  
Isostatic Adjustment ◽  
Alboran Basin ◽  
Mass Shifts

<p>The Messinian Salinity Crisis (MSC) was caused and terminated by changes in the Atlantic-Mediterranean connectivity in the western end of the Alboran Basin, a complex tectonic area affected by the Iberia-Africa collision and the presence of a subducted lithospheric slab beneath the Betic-Rif orogen.</p><p>The isostatic, tectonic and erosional effects on surface topography work on different spatial and temporal scales, and their relative contributions to the changes in connectivity and subsequent evaporite deposition and sea-level drop are difficult to constrain.</p><p>We perform 2D-planform flexural isostatic modeling using the Messinian Erosion Surface imaged in the Alboran Basin to reconstruct the topography and vertical motions of this region since the end of the MSC. The results constrain the original depth of the Messinian erosional features to test their consistency against the various models proposed for Mediterranean sea-level changes during the MSC. <br>We apply Glacial Isostatic Adjustment theory to quantify the time response of these vertical motions to the large MSC-related mass shifts (salinification, evaporite deposition and a kilometer-scale sea-level drop),  and their gravitational effects on sea-level in the Mediterranean. In particular, models for the Strait of Gibraltar allowus to identify the potential role of these effects as feedback mechanisms influencing the rates and duration of changes in the Atlantic-Mediterranean connectivity at the straits.  We will explore the possible implications of these for the timing of the closure of the last Atlantic-Mediterranean seaway.</p>

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor

Role of the allergist in diagnosis and management of patients with uveitis

JAMA ◽  
1966 ◽  
Vol 195 (3) ◽  
pp. 167-172 ◽  
Author(s):  
T. E. Van Metre
Keyword(s):  
Diagnosis And Management

The power of norms to sway fused group members

2018 ◽  
Vol 41 ◽  
Author(s):  
Winnifred R. Louis ◽  
Craig McGarty ◽  
Emma F. Thomas ◽  
Catherine E. Amiot ◽  
Fathali M. Moghaddam
Keyword(s):  
Evolutionary Anthropology ◽  
Normative Systems ◽  
Violent Extremism ◽  
Identity Fusion ◽  
Group Members

AbstractWhitehouse adapts insights from evolutionary anthropology to interpret extreme self-sacrifice through the concept of identity fusion. The model neglects the role of normative systems in shaping behaviors, especially in relation to violent extremism. In peaceful groups, increasing fusion will actually decrease extremism. Groups collectively appraise threats and opportunities, actively debate action options, and rarely choose violence toward self or others.

Elaborating the role of reflection and individual differences in the study of folk-economic beliefs

2018 ◽  
Vol 41 ◽  
Author(s):  
Kevin Arceneaux
Keyword(s):  
Decision Making ◽  
Individual Differences ◽  
Cognitive Processes ◽  
Evolutionary History ◽  
Behavioral Responses ◽  
History Of ◽  
Economic Beliefs

AbstractIntuitions guide decision-making, and looking to the evolutionary history of humans illuminates why some behavioral responses are more intuitive than others. Yet a place remains for cognitive processes to second-guess intuitive responses – that is, to be reflective – and individual differences abound in automatic, intuitive processing as well.

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