scholarly journals Erosional processes and paleo-environmental changes in the Western Gulf of Lions (SW France) during the Messinian Salinity Crisis

2005 ◽  
Vol 217 (1-2) ◽  
pp. 1-30 ◽  
Author(s):  
Johanna Lofi ◽  
Christian Gorini ◽  
Serge Berné ◽  
Georges Clauzon ◽  
A. Tadeu Dos Reis ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Messinian Salinity Crisis ◽  
Gulf Of Lions ◽  
Sw France

The Late Messinian salinity crisis and Late Miocene tectonism: Interaction and consequences on the physiography and post-rift evolution of the Gulf of Lions margin

2005 ◽  
Vol 22 (6-7) ◽  
pp. 695-712 ◽  
Author(s):  
Christian Gorini ◽  
Johanna Lofi ◽  
Cédric Duvail ◽  
Antonio Tadeu Dos Reis ◽  
Pol Guennoc ◽  
...  
Keyword(s):  
Late Miocene ◽  
Messinian Salinity Crisis ◽  
Gulf Of Lions

scholarly journals Calcareous dinoflagellate turnover in relation to the Messinian salinity crisis in the eastern Mediterranean Pissouri Basin, Cyprus

2007 ◽  
Vol 26 (2) ◽  
pp. 103-116 ◽  
Author(s):  
Katarzyna-Maria Bison ◽  
Gerard J. M. Versteegh ◽  
Frits J. Hilgen ◽  
Helmut Willems
Keyword(s):  
Mediterranean Basin ◽  
Phytoplankton Community ◽  
Environmental Changes ◽  
Eastern Mediterranean ◽  
Messinian Salinity Crisis ◽  
Low Diversity ◽  
Restricted Environment ◽  
The Mediterranean ◽  
Upper Tortonian ◽  
The Mediterranean Basin

Abstract. The extent to which the Messinian salinity crisis modified the initially Tethyan, eastern Mediterranean phytoplankton community has been investigated by monitoring the fate of calcareous dinoflagellate cyst assemblages prior to, during and after the salinity crisis in the Pissouri section (Cyprus). A rich, but low diversity open oceanic assemblage, dominated by Calciodinellum albatrosianum, is found in the upper Tortonian and lower Messinian. The upper Messinian (pre-evaporitic) sediments yield only few cysts but the assemblage is much more diverse and reflects unstable more neritic conditions (Bicarinellum tricarinelloides), fluvial influence (Leonella granifera) and varying, temporally increased salinities (Pernambugia tuberosa), probably related to the increasingly restricted environment. The basal Pliocene sediments reflect the return to normal marine conditions; the dinoflagellate assemblage is rich in cysts and again has a low diversity. However, in contrast to the C. albatrosianum-dominated upper Tortonian and pre-evaporitic Messinian sediments, L. granifera clearly dominates the basal Pliocene association just after the replenishment of the Mediterranean basin. Apart from this shift in dominance, the onset of the Pliocene is furthermore marked by the first appearance of Calciodinellum elongatum, which must have immigrated from the Atlantic Ocean. Lebessphaera urania, a postulated remnant of the Tethyan Ocean survived the salinity crisis, possibly in as yet unidentified marine refuges in the Mediterranean itself. Although the environmental changes caused by the Messinian salinity crisis did not lead to an extinction of calcareous dinoflagellate species of the Pissouri Basin, it resulted in a significant change in the assemblages and contributed to a more modern character of the Pliocene dinoflagellate association in the eastern Mediterranean.

Local environmental changes recorded by clay minerals in a karst deposit during MIS 3 (La Chauverie, SW France)

2011 ◽  
Vol 241 (1-2) ◽  
pp. 26-34 ◽  
Author(s):  
Abderrazak El Albani ◽  
Alain Meunier ◽  
Roberto Macchiarelli ◽  
Florian Ploquin ◽  
Jean-François Tournepiche
Keyword(s):  
Clay Minerals ◽  
Environmental Changes ◽  
Mis 3 ◽  
Sw France

Environmental changes across the onset of the Messinian salinity crisis: insights from the Piedmont Basin (NW Italy).

2020 ◽  
Author(s):  
Mathia Sabino ◽  
Daniel Birgel ◽  
Francesco Dela Pierre ◽  
Marcello Natalicchio ◽  
Jörn Peckmann
Keyword(s):  
Water Column ◽  
Environmental Changes ◽  
Water Layer ◽  
Major And Trace Elements ◽  
Messinian Salinity Crisis ◽  
Water Column Stratification ◽  
Bottom Waters ◽  
Calcareous Plankton ◽  
Nw Italy ◽  
Palaeoenvironmental Changes

<p>Since the discovery of the late Miocene (Messinian) Mediterranean Salt Giant more than 50 years ago, the environmental conditions that caused its formation have been debated. Such reconstruction suffers from the absence of modern analogues, the lack or scarcity of fossils (calcareous plankton and benthos, but also pollens), and the inaccessibility of the evaporites buried beneath the present-day Mediterranean seafloor. We investigate the palaeoenvironmental changes, which drove the formation of the Mediterranean Salt Giant at the onset of the Messinian salinity crisis (MSC) through high resolution sedimentological, petrographical, and geochemical (lipid biomarkers, major and trace elements) analyses of sedimentary successions of the Piedmont Basin (NW Italy). Shale/marl couplets deposited in intermediate to deep-water settings (200 – 1000 m) are targeted, representing the lateral equivalent of primary sulphate evaporites from shallow-water settings that accumulated between 5.97 and 5.60 Ma. We suggest that climate and hydrological changes affected the northern Mediterranean in the earliest stage of the MSC event, leading to an intensification of water column stratification. An upper water layer of marine water influenced by freshwater input was separated through a pycnocline from more evaporated, denser and oxygen-depleted bottom waters. The water column structure and pycnocline oscillation exerted pivotal control over the sedimentary products pertaining to the first stage of the MSC.</p>

scholarly journals Critical analysis of Mediterranean sea level limit cycles during the Messinian salinity crisis

2021 ◽  
Vol 19 ◽  
pp. 1-11
Author(s):  
Mark Baum
Keyword(s):  
Mediterranean Sea ◽  
Sea Level ◽  
Limit Cycles ◽  
Model Equation ◽  
Environmental Changes ◽  
Model Parameters ◽  
Messinian Salinity Crisis ◽  
Strait Of Gibraltar ◽  
Proposed Model ◽  
The Mediterranean

The Messinian Salinity Crisis (5.97-5.33Ma) may be one of the most significant periods of sea-level change in recent geologic history. During this period, evaporite deposition throughout the Mediterranean basin records a series of dramatic environmental changes as flow through the Strait of Gibraltar was restricted. In the first stage of evaporite deposition, cycles of gypsum appear in shallow basins on the margins of the Mediterranean. The complex environmental history giving rise to these cycles has been investigated for decades but remains controversial. Notably, whether the evaporites are connected to significant changes in Mediterranean sea level is an open question. In one proposed model, competition between tectonic uplift and erosion at the Strait of Gibraltar gives rise to selfsustaining sea-level oscillations—limit cycles—which trigger evaporite deposition. Here I show that limit cycles are not a robust result of the proposed model and discuss how any oscillations produced by this model depend on an unrealistic formulation of a key model equation. First, I simplify the model equations and test whether limit cycles are produced in 64 million unique combinations of model parameters, finding oscillations in only 0.2% of all simulations. Next, I examine the formulation of a critical model equation representing stream channel slope over the Strait of Gibraltar, concluding that a more realistic formulation would render sea-level limit cycles improbable, if not impossible, in the proposed model.

Linking transcription, RNA polymerase II elongation and alternative splicing

2020 ◽  
Vol 477 (16) ◽  
pp. 3091-3104 ◽  
Author(s):  
Luciana E. Giono ◽  
Alberto R. Kornblihtt
Keyword(s):  
Gene Expression ◽  
Alternative Splicing ◽  
Rna Polymerase Ii ◽  
Environmental Changes ◽  
Transcription Elongation ◽  
Single Gene ◽  
Regulation Of Gene Expression ◽  
Regulation Of Transcription ◽  
Stepping Stones ◽  
Eukaryotic Transcription

Gene expression is an intricately regulated process that is at the basis of cell differentiation, the maintenance of cell identity and the cellular responses to environmental changes. Alternative splicing, the process by which multiple functionally distinct transcripts are generated from a single gene, is one of the main mechanisms that contribute to expand the coding capacity of genomes and help explain the level of complexity achieved by higher organisms. Eukaryotic transcription is subject to multiple layers of regulation both intrinsic — such as promoter structure — and dynamic, allowing the cell to respond to internal and external signals. Similarly, alternative splicing choices are affected by all of these aspects, mainly through the regulation of transcription elongation, making it a regulatory knob on a par with the regulation of gene expression levels. This review aims to recapitulate some of the history and stepping-stones that led to the paradigms held today about transcription and splicing regulation, with major focus on transcription elongation and its effect on alternative splicing.

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