Messinian Development Basin (Term Paper Sample)

Messinian Development Basin
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The Messinian event is a geographical phenomenal that took place millions of years ago. Man has put much effort trying to study how the earth structure is and its environs. This curiosity has led him to study the geographical structure of the earth. This would include mountains, rivers, plains, volcanoes and even basins. The formation of all this geographical features affects the climate weather and the topographical lands scape of the earth. This is nature which man cannot control but only try to learn from it. Nature fury is among the most feared hazards by man. They occur due to the different geographical formation of the earth.
The Messinian event can also be referred to as the Messinian salinity crisis. During its last stages, it was called the Lago Mare period or event. These were geological events that took place millions of years ago when the Mediterranean was undergoing cycles. During these cycles, the Mediterranean nearly went in to complete desiccation until the late stages of the messianic age. Geological scientists estimate the amount of time it took place to be 5.33 million years ago. The geological process continued to a stage called the Zanclean flood where the larger Atlantic Ocean reclaimed and took over the basin.
Scientists have collected samples of sediments from the sea floor for testing and further analysis. These samples include mineral, fossil plants and soils from the bottom of the sea bed. The samples revealed that five million years ago during the Miocene periods a geographical event occurred that forever changed the face of the Mediterranean ocean till today. The straight Gibraltar of the Mediterranean closed for the first time. The Mediterranean Sea desiccated in about five million years ago. This happened again for the last time when it closed again. The Mediterranean experiences dry climatic conditions of the millennium. As a result, the Mediterranean evaporated in to a dry basin. The basin was 3 to 5 kilometres deep below the sea level.
The basin had a few hyper salines which allowed it to continue getting fresh water from the rivers that drained in to it. This allowed the basin to slowly resume to its normal condition until the periods which strait of Gibraltar was opened. These changes forever affected the state of the Mediterranean Sea. It became salty because of the near isolation by the strait of Gibraltar. Until today, the Mediterranean is said to be saltier than North Atlantic Ocean. These high rates of evaporation then caused the levels of salt in the sea to rise to their highest levels (Poel, 1994).
In later years, the tectonic activities increased within the earth crust, and this caused some grounds to rise higher than others. It was till then that the Messinian salt deposits were pushed upwards to an outcropping state. These areas had so much salt and were frequently studied by the geologists because of the rapid changes of climate around these areas. Some of the regions affected by the salinity crisis were Northeast Libya, Messina in Sicily, Italy and Southern Spain (Robertson, 2006).
This period was named Messinian by a geologist called Eporch in 1867 because of the region Messina. In 1961, a geological feature was discovered 600 feet beneath the sea floor. This happened during a seismic survey of the Mediterranean floor. The feature was accompanied by numerous contours on the sea floor just above it. Geologists suggested that the presence of the contours showed that it had evenly been laid over the years consistently. Many theories have been formed around it since them trying to explain its formation. The formation of this layer was due to the salt deposition that took place in the late Miocene age.
In 1970, scientist took in to the Mediterranean equipment’s to drill and take samples of the salt. The samples have been preserved as evidence of the Messinian salinity crisis. The samples were later studied, analysed and dated by the scientists (Morris, 1996).
Over the years, due to the various tectonic activities in the earth crust, the deposits of the Messinian periods have since been carried to the surface above the sea level. Geologists date the starting of the Messinian salt crisis to 3 million years ago. This period is also said to contain the, late stages of the Messinian period. It was characterised by depositional events, fluctuation of the sea levels, erosion and tectonic activities.
It was during these periods that the Mediterranean - Atlantic strait began to close tight. This happened several times for a shorter period of time depending on the scales applied by the geologists. This resulted to the desiccation of the sea, and finally it was cut off from the Atlantic Ocean. The Mediterranean Sea level was lowered drastically, and this caused massive erosions during the first periods of the dry seasons. Huge canyons were, and salt deposits formed. The result was a cyclic deposition forming a lake-sea basin. It was at this late stage of the Messinian event that it was also named Lago Mare period (Robertson, 2006).
During the late Messinian period, a number of cycles and events took place leading to the geographical nature of the sea. The Messinian salts are of larger and high salinity compared to the Atlantic. This is because as the salty Atlantic water was washed in to the Mediterranean basin, intense evaporation took place resulting to high periods of hyper salinity. This was a cycle of the basin filling up with water and drying. The refilling of the basin was by inlets of water caused by the tectonic movement of the plates and also few rivers ‘which fed into’ the basin (Poel, 1994).
Each cycle had its own sediments deposited in the sea bed. As water gushed in the basin, in every cycle it left along sediments after evaporating. The finest sediments were deposited at the bottom of the sea resulting to an even lamination of the sea floor. The depth of the sea gradually reduced due to the deposits. Over the years, the lamination became more irregular resulting to the wave like form of the sea bed.
In the last stages of the Messinian cycle, two theories of how the basins were formed came to be. They used the concept of deposition to explain the phenomenal. One was called the synchronous deposition which existed before the key stage of erosion. The other phase was called the diachronous deposition. Some scholars explain that the deposition was synchronous. This mainly occurred in the shallow basins. They further explained that when the Mediterranean Sea level fell only the shallow basin...