Mid-Atlantic Ridge in Iceland. Slicing through the center of Iceland is the Mid-Atlantic Ridge. This is the boundary between the North American and Eurasian tectonic plates. Tectonic plates are the enormous slabs that make up the Earth's crust.
The Mid-Atlantic Ridge is on a divergent boundary where there is a lot of volcanic activity. An island formed from these volcanic eruptions. The hot magma reaches the surface, cooled, and eventually formed the land we now know as Iceland.