Halfway through the Cenozoic, the Era in which we live, a broad land bridge connected Europe and North America. Then, about 30 million years ago, two rift zones developed in this bridge; over time they would open to form the North Atlantic and the land between the rifts would become Greenland. Today, basalt flows on the east and west coasts of the island bear witness to the process of its emancipation.
The eastern rift remains active as the North Atlantic spreading zone, where new ocean floor is produced and where the Eurasian and North American plates are pulling apart. Volcanism is common along such "mid-oceanic ridges" and the volcanic island of Iceland formed above the North Atlantic ridge, first emerging from the sea some 16 million years ago; volcanic activity continues on the island today and the rifting process is clearly visible in some areas. Iceland is a country that straddles two tectonic plates!
