About 140 million years ago, Greater Adria was a Greenland-size landmass (submerged portions in gray-green). VAN HINSBERGEN ET AL., GONDWANA RESEARCH (2019)
About 100 million years ago, a Greenland-size landmass called Greater Adria collided with southern Europe and shattered into pieces as it was shoved beneath that continent. Only a fraction of Greater Adria’s rocks, scraped off in the collision, remained on Earth’s surface for geologists to discover.
Rather than simply moving north with no change in its orientation, Greater Adria spun counterclockwise as it jostled and scraped past other tectonic plates, Although the tectonic collision happened at speeds of no more than 3 to 4 centimeters per year, the inexorable smash-up shattered the 100-kilometer-thick bit of crust and sent most of it deep within Earth’s mantle.
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