A study of microfossils from oceanic core deposits reveals the environmental conditions that existed at high latitudes during an important era in Earth’s history.
At the start of the Eocene era around 55 million years ago, the poles of the Earth are said to have been devoid of ice. However, during the early Oligocene era 25 millions years later, Antarctica and Greenland developed ice sheets.
“This change from greenhouse to icehouse conditions resulted from decreasing greenhouse gas concentrations and changes in Earth's orbit”, said Dr Ian Harding from the University of Southampton’s Schools of Ocean and Earth Sciences. “However, the opening or closing of various marine gateways and shifts in ocean currents may also have influenced regional climate in polar high-latitudes”.
The parting of Greenland and Eurasia resulted in the fractional or complete immersion of prehistoric land barriers like the Vøring Plateau in the Norwegian continental border.
Harding and Dr James Eldrett, Harding’s former doctorate student, Dr James Eldrett, reconstructed the Vøring Plateau’s environmental conditions at this time by carefully studying the fossilised remnants of organic remains of dinoflagellates in sediment cores.
The evidences found in the sediment cores indicate the evolution of shallow marine habitats in the Vøring Plateau in the early Eocene. Nevertheless, the discovery of fossilised species suggests that northerly areas of the plateau and the top of the Vøring Escrapment were still above water level.
In the late Eocene, the sediments were only from planktons, indicating that the whole plateau has been submerged. This shows that marine links were formed between different Nordic sea basins earlier than previously thought.
At the start of the Eocene era around 55 million years ago, the poles of the Earth are said to have been devoid of ice. However, during the early Oligocene era 25 millions years later, Antarctica and Greenland developed ice sheets.
“This change from greenhouse to icehouse conditions resulted from decreasing greenhouse gas concentrations and changes in Earth's orbit”, said Dr Ian Harding from the University of Southampton’s Schools of Ocean and Earth Sciences. “However, the opening or closing of various marine gateways and shifts in ocean currents may also have influenced regional climate in polar high-latitudes”.
The parting of Greenland and Eurasia resulted in the fractional or complete immersion of prehistoric land barriers like the Vøring Plateau in the Norwegian continental border.
Harding and Dr James Eldrett, Harding’s former doctorate student, Dr James Eldrett, reconstructed the Vøring Plateau’s environmental conditions at this time by carefully studying the fossilised remnants of organic remains of dinoflagellates in sediment cores.
The evidences found in the sediment cores indicate the evolution of shallow marine habitats in the Vøring Plateau in the early Eocene. Nevertheless, the discovery of fossilised species suggests that northerly areas of the plateau and the top of the Vøring Escrapment were still above water level.
In the late Eocene, the sediments were only from planktons, indicating that the whole plateau has been submerged. This shows that marine links were formed between different Nordic sea basins earlier than previously thought.
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