An international study has revealed details about the Mediterranean salinity crisis of 6 million years ago, offering new perspectives on the geological and climatic evolution of the region
A new study conducted by a team of international researchers, with the participation ofNational Institute of Geophysics and Volcanology (INGV), has brought to light important discoveries regarding the salinity crisis occurred in the Mediterranean about 6 million years ago, which caused the progressive drying of the pelvis.
According to the research “Causes and consequences of the Messinian salinity crisis” recently published in Nature, the opening and closing of oceans and seas, related to the movements of lithospheric plates, often lead to the formation of marginal basins with limited water exchange with the open ocean. These periods of limited exchange can lead to the accumulation of enormous evaporite deposits, known as “salt giants”, such as that found in the Mediterranean during the Messinian salinity crisis.
Fabio Florindo, researcher at INGV and co-author of the study, underlined the importance of these findings: "These enormous evaporite deposits have formed episodically throughout Earth's history and have had a significant impact on the carbon cycle and global climate.".
During the Messinian crisis, the Mediterranean underwent an important transformation due to the progressive closure of the connection with the Atlantic Ocean.
"This event", goes on Florindo, “led to a significant decrease in water levels in the Mediterranean and the deposition of over 1 million cubic kilometers of salt, in the form of gypsum and halite deposits, in its basins”.
The implications of these evaporite deposits on the chemical composition of the oceans and on the global climate balance have been explored by scholars. The removal of calcium from the oceans through the deposition of calcium sulfate has caused a number of changes, including an increase in ocean pH, a decrease in the partial pressure of atmospheric carbon dioxide, and global cooling.
Around 5.3 million years ago, this period of isolation came to an epic conclusion with a massive flood from the Atlantic, known as the Zanclean event, which brought marine conditions back to the Mediterranean.
This study offers an important window into the geological past of the Mediterranean and the evolution of our planet, offering valuable insights to better understand the climatic and environmental processes that have shaped the Earth over the millennia.
Cover photo by Ron Blakey
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A new study conducted by a team of international researchers, with the participation ofNational Institute of Geophysics and Volcanology (INGV), has brought to light important discoveries regarding the salinity crisis occurred in the Mediterranean about 6 million years ago, which caused the progressive drying of the pelvis.
According to the research “Causes and consequences of the Messinian salinity crisis” recently published in Nature, the opening and closing of oceans and seas, related to the movements of lithospheric plates, often lead to the formation of marginal basins with limited water exchange with the open ocean. These periods of limited exchange can lead to the accumulation of enormous evaporite deposits, known as “salt giants”, such as that found in the Mediterranean during the Messinian salinity crisis.
Fabio Florindo, researcher at INGV and co-author of the study, underlined the importance of these findings: "These enormous evaporite deposits have formed episodically throughout Earth's history and have had a significant impact on the carbon cycle and global climate.".
During the Messinian crisis, the Mediterranean underwent an important transformation due to the progressive closure of the connection with the Atlantic Ocean.
"This event", goes on Florindo, “led to a significant decrease in water levels in the Mediterranean and the deposition of over 1 million cubic kilometers of salt, in the form of gypsum and halite deposits, in its basins”.
The implications of these evaporite deposits on the chemical composition of the oceans and on the global climate balance have been explored by scholars. The removal of calcium from the oceans through the deposition of calcium sulfate has caused a number of changes, including an increase in ocean pH, a decrease in the partial pressure of atmospheric carbon dioxide, and global cooling.
Around 5.3 million years ago, this period of isolation came to an epic conclusion with a massive flood from the Atlantic, known as the Zanclean event, which brought marine conditions back to the Mediterranean.
This study offers an important window into the geological past of the Mediterranean and the evolution of our planet, offering valuable insights to better understand the climatic and environmental processes that have shaped the Earth over the millennia.
Cover photo by Ron Blakey
Useful links:
Figure 1: Evaporitic phases of the Messinian salinity crisis (MSC). a, Map of the Mediterranean region with the most important seas, straits and mountain ranges. b–d, Schematic maps of the Mediterranean and Paratethys during three evaporitic phases with the main outcropping sites on land. This series of maps illustrates the sequence of evaporite units that define the MSC during the restriction and isolation of the Mediterranean from the Atlantic 
Figure 2: Stratigraphy of the Messinian salinity crisis in different basin contexts. a, Schematic map of the Mediterranean with indication of the marginal areas, the shallow basins with barriers, the intermediate basins and the deep central basins.
b, Schematic cross section of the Mediterranean with MSC deposits in different basin contexts. The numbers in the levels refer to: 1, lower primary chalk (PLG) phase; 2, halite; 3, upper chalk phase (UG).
c, Age constraints and distribution of MSC deposits in different basin contexts. Stratigraphic records of the Messinian Salinity Crisis (MSC) reflect basin depth and tectonic environment.
Figure 3:
Geodynamic context of the Messinian salinity crisis.
a, Schematic topography of the Strait of Gibraltar region before the Messinian salinity crisis, indicating the paleogeography of the Mediterranean-Atlantic connection. The labels illustrate the ages and mechanisms of vertical motion that constrained the Atlantic-Mediterranean connection (~5,33-7 Ma).
b, Schematic representation of lithospheric plate morphology beneath Gibraltar at approximately 8 Ma. Arrows illustrate absolute plate motions for Africa and Iberia with slower Betic central-eastern motion. The configuration required for connecting or restricting the Mediterranean from the Atlantic was controlled by the Africa-Iberia convergence. slower eastern Betic.
