Greater Adria, a long-lost continent the size of Greenland, has been discovered in southern Europe. New geological evidence – reported in the journal Gondwana Research – suggests this landmass first split from what is now France, Spain and North Africa before being pulled down into the depths of several subduction zones (places where one slab of the Earth’s crust is forced beneath another).
As plate tectonics drove Greater Adria beneath what became southern Europe, the bulk of it ultimately met its demise in the furnace that is our planet’s mantle. Much of the remainder (the top layer) was violently shaved off, similar to frost being scraped off a car’s windscreen, and piled onto the overriding pieces of crust. These remnants went on to form mountains in the Alps, Balkans, Greece, Italy and Turkey. The new study also highlights several splinters of Greater Adria that broke off and avoided the aforementioned geological wrecking rooms; these preserved relics are possible to see today in the Istria region of Croatia, northern Italy (dotted between Venice and Turin) and southern Italy (the heel section of the country’s ‘boot’).
How did this lost continent go so long without being discovered?
The Mediterranean region is a complex puzzle in geological terms, and the fact that evidence of Greater Adria is spread over some 30 countries (each with their own mapping and surveying techniques, terminology etc) made compiling corroborative data difficult. The fact that Greater Adria started to meet its demise some 100 million years ago also didn’t help the process. The success of the latest study is the result of the team spending a decade deciphering an overflow of both geological and geophysical data from across the region. The software program GPlates has also aided their efforts.
